Abstract: There is a need to maintain or enhance the magnetic field correction accuracy of a physics package while making the physics package more compact and portable. A triaxial magnetic field correction coil is provided inside a vacuum chamber surrounding a clock transition space having atoms disposed therein. The triaxial magnetic field correction coil is formed into a shape such that it is possible to correct, for magnetic field components of three axial directions passing through the clock transition space, a constant term, a first order spatial derivative term, a second order spatial derivative term, a third or higher order spatial derivative term, or some given combination of these terms. The triaxial magnetic field correction coil can be used in, for example, a physics package for an optical lattice clock.

Abstract: A device implementing a real time clock integrated module for outputting data indicating a time-of-day. The real time clock integrated module includes: a high-precision oscillator or atomic clock having an accuracy of 50 ppb (parts per billion) or better; a timing circuit for generating time-of-day data according to a clock signal outputted from the oscillator or atomic clock; a power source allowing the timing circuit to maintain time when the device is powered off. The timing circuit includes a real time clock and a logic device storing a timestamp. The timing circuit is configured when the device is powered off to update the timestamp value based on the oscillator or atomic clock and to generate a time reference signal and to provide to the device the updated timestamp value and the time reference signal that the device can use as a time reference once the device is powered up again.

Abstract: An optical lattice clock includes a clock transition space having disposed therein an atom group trapped in an optical lattice, and a triaxial magnetic field correction coil for correcting the magnetic field of the clock transition space. Additionally, in a correction space that includes the clock transition space and is larger than the clock transition space, a photoreceiver promotes the clock transition of the atom group trapped in the optical lattice and acquires a clock transition frequency distribution for the correction space. Further, a corrector corrects the magnetic field of the triaxial magnetic field correction coil on the basis of the frequency distribution measured by the photo receiver.

Abstract: A device to extract physiological information has at least one laser emitter. At least one optical detector is used to detect a change in optical power absorption. The laser emitter and optical detector are wire bonded into a chip scale module.

Abstract: An atomic clock employs alkali metal atoms such as cesium normally used for microwave atomic clocks but with optical stimulation. While alkali metals provide light emissions having a spectral width being as much as 107 wider (and hence less precise) than alkali earth materials commonly targeted for optical atomic clocks, the present inventors have determined that this disadvantage is significantly reduced by improved signal-to-noise ratio in the obtained signal making practical an atomic clock with improved size, weight, and power consumption.

Abstract: Magnetic element including a first ferromagnetic layer having a first magnetization including a stable magnetization vortex configuration having a vortex core. The first ferromagnetic layer includes an indentation configured such that the vortex core nucleates substantially at the indentation. Upon application of an external magnetic field in a first field direction, the vortex core moves along a first path and the first magnetization rotates around the vortex core in a counterclockwise direction. Upon application of the external magnetic field in a second field direction opposed to the first field direction, the vortex core moves along a second path and the first magnetization rotates around the vortex core in a clockwise direction. Both the first and second field path are substantially identical and move the vortex core away from the indentation.

Abstract: An exemplary wearable sensor unit includes 1) a magnetometer comprising a vapor cell comprising an input window and containing an alkali metal, and a light source configured to output light that passes through the input window and into the vapor cell along a transit path, and 2) a temperature control circuit external to the vapor cell and configured to create a temperature gradient within the vapor cell, the temperature gradient configured to concentrate the alkali metal within the vapor cell away from the transit path of the light.

Abstract: A phased-array MASER detector for synthetic aperture interferometric three-dimensional imaging. The detector elements, for example 102-106 zero bias Schottky detector diodes with sufficient sensitivity to reliably detect various values of MASER radiation, are arranged in layers offset in three dimensions. The phased-array MASER detector is particularly useful for detecting characteristics in a biological object using low energy (2-10 Watts), coherent MASER radiation. MASER intensity data of an interferometric pattern is collected by the detector array, is deconvolved, and is used to generate three-dimensional energy activity maps for a given time slice or on a time-shifting basis.

Abstract: A miniature atomic clock with pulse mode operation. The clock includes: a local oscillator; a dual-frequency laser source; a pulsing element to pulse the output signal from the source according to a Ramsey-type interrogation sequence having pulses with duration T1 separated by intervals with duration T2; an alkaline vapour microcell; a photodiode; a feedback control loop for controlling the microwave frequency of the local oscillator; and a feedback control loop for controlling the optical frequency of the source by using a pulse control block receiving the output signal from the photodiode and the interrogation sequence, and providing a correction signal to the source. During the period T1, the block extracts an error signal from the output signal received from the photodiode and generates the correction signal from the error signal. During the period T2, the block resets the error signal to zero and generates the correction signal by extrapolation.

Abstract: The invention relates to a differential detection of double-modulation (DM) CPT method and a system for implementing the method of this invention. The method comprises the following steps: Generating a coherent bichromatic light, in which the polarization and the relative phase are synchronously modulated. The DM light interacts with a quantum resonance system and prepares it into a CPT state. Then the polarization of coherent bichromatic light is switched from circular polarization to linear polarization. After interacting with the CPT state prepared in the previous stage, the constructive and destructive quantum interference occur simultaneously. The polarization of the transmitted light from the quantum resonance system is converted and spatially separated. Then two CPT signals, detected by balanced photodetectors, are observed with constructive and destructive interference respectively.

Abstract: The invention relates to a coherent population trapping (CPT) phase modulation and demodulation method and a system for implementing the method of this invention. The method comprises the following steps: Generating a coherent bichromatic light, in which the relative phase between the two frequency components is modulated with proper modulation depth. The phase modulated coherent bichromatic light interacts with a quantum resonance system, and prepares it alternately into two inverted CPT states. Detecting the transmitted light with a photodetector, two inverted dispersive CPT signals in two detection windows are observed. With synchronous phase demodulation, a CPT error signal is obtained, which is used for locking the local oscillator to implement a CPT atomic clock.

Abstract: An atomic oscillator including an oscillator that outputs an oscillation signal, a light emitter to which a signal based on the oscillation signal is inputted, an atomic cell, a light receiver that detects the light passing through the atomic cell and outputs a detection signal, a first temperature controller, and a control circuit, and the control circuit has a first mode including the process of operating the light emitter and the first temperature controller and the process of causing the oscillator to output the oscillation signal, a second mode including the process of causing the light emitter and the first temperature controller to stop operating and the process of causing the oscillator to stop outputting the oscillation signal, and a third mode including the process of causing the light emitter to stop operating, the process of operating the first temperature controller, and the process of causing the oscillator to stop outputting the oscillation signal.

Abstract: An ion trap device is disclosed with a method of manufacturing thereof including a substrate, first and second RF electrode rails, first and second DC electrodes on either upper or lower side of substrate, and a laser penetration passage connected to ion trapping zone from outer side of the first or second side of substrate. The substrate includes ion trapping zone in space defined by first and second sides of substrate separated by a distance with reference to width direction of ion trap device. The first and second RF electrode rails are arranged in parallel longitudinally of ion trap device. The first RF electrode is arranged on upper side of first side, the second DC electrode is arranged on lower side of first side, the first DC electrode is arranged on upper side of second side, and the second RF electrode rail is arranged on lower side of second side.

Abstract: An integrated microfabricated sensor includes a sensor cell having a cell body, a first window attached to the cell body, and a second window attached to the cell body. The cell body laterally surrounds a cavity, so that both windows are exposed to the cavity. The sensor cell contains a sensor fluid material in the cavity. The cavity has concave profiles at cell body walls, so that the cavity is wider in a central region, approximately midway between the first window and the second window, than at the first surface and at the second surface. The cell body walls of the cell body have acute interior angles at both windows. The cell body is formed using an etch process that removes material from the cell body concurrently at the first surface and the second surface, forming the acute interior angles at both the first surface and the second surface.

Abstract: A method is disclosed for increasing an intensity of a signal detected in a spectroscopy device using a vapor cell and a spectroscopy device using the same. An operation method of the spectroscopy device may include: causing a first light for exciting an atom trapped in a vapor cell in a first hyperfine ground state to a first excited state to be incident on the vapor cell; causing a second light for exciting an atom trapped in the vapor cell in a second hyperfine ground state to a second excited state to be incident on the vapor cell; causing a third light for exciting the atom in the second excited state to a third excited state to be incident on the vapor cell; and detecting fluorescence which is emitted while the atom in the third excited state returns to the ground state.

Abstract: In a resonance generation method, a Ramsey resonance is generated by repeating a first period and a second period. In the first period, an atomic cell, in which an alkali metal atom is accommodated and a hydrocarbon film is disposed on an inner wall, is irradiated with light having a first intensity while sweeping a center frequency within a sweep range, and a center frequency of light with which the atomic cell is to be irradiated in a next first period is determined based on a light intensity signal obtained by detecting light transmitted through the atomic cell. In the second period, an intensity of light incident on the atomic cell is reduced as compared with the first intensity.

Abstract: Embodiments of the present disclosure generally relate to a write head for a magnetic recording device. The write head includes a spin torque oscillator (STO) that has a seed layer formed on a write pole, a spin polarization layer (SPL) formed on the seed layer, a first spacer layer formed on the SPL, a field generation layer (FGL) formed on the first spacer layer, a second spacer layer formed on the FGL, and a notch formed on the second spacer layer. The FGL and the notch are antiferromagnetically coupled through the second spacer layer and thus increases the FGL angle and improves the write capabilities of the write head.

Abstract: An integrated microfabricated alkali vapor cell sensor includes two alkali vapor regions, with a signal path through each. One or two signal emitters, with associated optical signal rotators, such as quarter wave plates, provide circularly polarized input signals into the alkali vapor regions, so that a first signal through the first alkali vapor region is circularly polarized in an opposite direction from a second signal through the second alkali vapor region. Output signals from the two alkali vapor regions are transformed to linearly polarized signals and then measured by one or more signal detectors. A first Larmor frequency is estimated from the output signal from the first alkali vapor region, and a second Larmor frequency is estimated from the output signal from the second alkali vapor region. A heading error-free Larmor frequency is estimated from the first Larmor frequency and the second Larmor frequency.

Abstract: In an example, an optical gimbal is described, the optical gimbal comprising: a pulse generator configured to generate at least two coherent beam splitting pulses; a first optical beam director configured to tilt the vector of the beam splitting pulses by an angle ?; an atom source configured to allow the beam splitting pulses to manipulate trapped atoms within the atom source; a processor configured to receive the angle ?, and control the pulse generator and the beam director; a detector coupled to the atom source configured to measure a final population of the atoms in different states.

Abstract: This oscillator comprises: a source generating an incident optical wave at a pulsation frequency ?; an optomechanical resonator, having optical resonances at the pulsation frequency ? and mechanical resonances at a frequency f1 and generating, from the incident optical wave, emergent optical waves at the pulsation frequencies ? and ??2?f1, and an acoustic wave at frequency f1; and, a photodiode delivering a useful signal at frequency f1 from the emergent waves. This oscillator further comprises: an acoustic propagation means for propagating the acoustic wave over a distance in order to produce a delayed acoustic wave; a means for converting the delayed acoustic wave into a delay signal at the frequency f1; and, a control loop, processing the delay signal in order to obtain a control signal applied to the source.

Abstract: Techniques are provided for decorrelation of intermodulation products in mixer circuits. A circuit implementing the techniques according to an embodiment includes four switches. Each of the switches comprise a complementary pair of n-channel and p-channel metal oxide semiconductor (NMOS/PMOS) field effect transistors (FETs). The NMOS/PMOS FETs include a source port, a drain port, and a gate port. The gate port is configured to receive an oscillator signal. The circuit also includes electrical conductors to couple the four switches into a double-balanced passive ring configuration to generate an output signal as a mix of an input signal and the oscillator signal. The output signal includes a third order intermodulation (IM3) product. The circuit further includes a voltage bias generator to generate a bias voltage to bias the input signal and the output signal. The magnitude and phase of the IM3 product are determined, at least in part, by the bias voltage.

Abstract: In disclosed apparatus, a plurality of optical waveguides monolithically integrated on a surface ion trap substrate deliver light to the trapping sites. Electrical routing traces defined in one or more metallization levels deliver electrical signals to electrodes of the surface electrode ion trap. A plurality of photodetectors are integrated on the substrate and arranged to detect light from respective trapping sites.

Abstract: Some variations provide an atomic vapor-cell system comprising: a vapor-cell region configured with vapor-cell walls for containing an atomic vapor; and a coating disposed on at least some interior surfaces of the walls, wherein the coating comprises magnesium oxide, a rare earth metal oxide, or a combination thereof. The atomic vapor-cell system may be configured to allow at least one optical path through the vapor-cell region. In some embodiments, the coating comprises or consists essentially of magnesium oxide and/or a rare earth metal oxide. When the coating contains a rare earth metal oxide, it may be a lanthanoid oxide, such as lanthanum oxide. The atomic vapor-cell system preferably further comprises a device to adjust vapor pressure of the atomic vapor within the vapor-cell region. Preferably, the device is a solid-state electrochemical device configured to convey the atomic vapor into or out of the vapor-cell region.

Abstract: Millimeter wave energy is provided to a spectroscopy cavity of a spectroscopy device that contains interrogation molecules. The microwave energy is received after it traverses the spectroscopy cavity. The amount of interrogation molecules in the spectroscopy cavity is adjusted by activating a precursor material in one or more sub-cavities coupled to the spectroscopy cavity by a diffusion path to increase the amount of interrogation molecules or by activating the getter material in one or more sub-cavities coupled to the spectroscopy cavity by a diffusion path to decrease the amount of interrogation molecules.

Abstract: An atomic oscillator includes an atom cell that includes a first portion and a second portion at a position different from the first portion, and contains alkali metal atoms, a light emitting element that emits light for exciting the alkali metal atoms toward the atom cell, a first temperature measurement element that measures the temperature of the first portion, a first temperature control element that controls a temperature of the first portion based on the measurement result of the first temperature measurement element, a second temperature measurement element that is disposed in a portion having thermal resistance equal to or higher than thermal resistance between the first portion and the second portion, and measures a temperature of the portion, a second temperature control element that controls the temperature of the second portion to be higher than the temperature of the first portion based on the measurement result of the second temperature measurement element or information on temperature control p

Abstract: An atomic oscillator includes an atom cell that includes walls defining an internal space in which alkali metal atoms are contained, a light emitting element that emits light for exciting the alkali metal atoms, and a light detecting element that detects the light transmitted through the atom cell, in which the atom cell includes a first portion in which gaseous alkali metal atoms are contained and through which light from the light emitting element passes along an x-axis, a second portion in which liquid or solid alkali metal atoms are contained, and a third portion that is positioned between the first portion and the second portion and couples the first portion and the second portion, and in the third portion, a distance between two walls facing each other along a y-axis orthogonal to the x-axis decreases from the first portion toward the second portion along the y-axis at a constant decrease rate.

Abstract: An atomic oscillator includes: an atom cell in which alkali metal atoms are accommodated; a light-emitting element that emits light beams for exciting the alkali metal atoms toward the atom cell; a shield that includes a first member, a second member, and a high thermal resistance portion and accommodates the atom cell, the first member and the second member being members having a magnetic shielding property, and the high thermal resistance portion being provided between the first member and the second member and having a thermal resistance higher than thermal resistances of the first member and the second member; a temperature control element that controls a temperature of the first member; a heater that is thermally coupled to the second member; and a light-receiving element that receives light beams passing through the atom cell.

Abstract: A frequency signal generation apparatus includes a light source, an atom cell with gaseous alkali metal atoms and a buffer gas enclosed therein, through which light output from the light source passes, and a container with a gas containing gas molecules in common with the buffer gas enclosed, housing the atom cell, wherein pressure of the common gas molecules is substantially the same within the atom cell and within the container.

Abstract: The present invention includes a device, a system, and a method for enhancing a particle separation efficiency, including a particle charging device adapted to impart predominately unipolar charging on a plurality of particles in a fluid stream, e.g. a gas stream; wherein the particle charging device is positioned upstream from and adapted to provide the plurality of particles charged by the particle charging device to a particle deflection device capable of separating the particles charged by the particle charging device from a core fluid flow that is substantially free of dust particles.

Abstract: An atomic oscillator includes an atom cell that accommodates an alkali metal atom, a heating device that heats the atom cell, a container that includes a first magnetism shielding member that is disposed between the heating device and the atom cell and a second magnetism shielding member that is disposed on the side opposite the atom cell with respect to the heating device to shield the atom cell from magnetism produced by the heating device, and a thermally insulating member disposed between the first member and the second member.

Abstract: An atomic oscillator includes: a light-emitting element; an atom cell that includes a first surface on which light beams from the light-emitting element are incident and a second surface from which the light beams incident on the first surface are emitted and accommodates alkali metal atoms in a gas state; a shield that accommodates the atom cell and has a magnetic shielding property, the shield having an opening; a heat transfer member that is in contact with a portion of the atom cell via an opening of the shield and has a thermal conductivity higher than a thermal conductivity of the atom cell; a temperature control element that is in contact with the heat transfer member and controls a temperature of the atom cell; and a light-receiving element that receives the light beams emitted from the second surface.

Abstract: A frequency signal generation device includes a substrate, a light source that is disposed on a surface of the substrate, and an atom cell that is disposed on the surface of the substrate. The atom cell contains gaseous alkali metal atoms and includes a first portion through which light emitted from the light source passes, a second portion housing a liquid alkali metal atom, and a third portion which connects the first portion to the second portion. A marker is provided that indicates a direction in which the liquid alkali metal atoms move to the third portion by gravity when the surface is vertically oriented.

Abstract: A frequency signal generation apparatus includes an atom cell including a first part including gaseous alkali metal atoms and a second part including liquid alkali metal atoms. A first temperature controller controls the first part's temperature. A second temperature controller controls the second part's temperature to be lower than that of the first part. First and second temperature detectors respectively detect the first and second parts' temperatures. The first temperature controller and the second temperature detector are thermally connected. The second temperature controller and the first temperature detector are thermally connected. The phase of a temperature control loop of the first part including the first temperature controller and the first temperature detector and the phase of a temperature control loop of the second part including the second temperature controller and the second temperature detector are different.

Abstract: The invention relates to a gas cell for an atomic sensor, comprising an optical cavity provided with at least one optical window (9) and fillable with a gas. The cell also comprises a sealing cup comprising a cavity mouth, a channel mouth, and a sealing access, as well as a membrane which hermetically closes the sealing access of the sealing cup. The membrane can be plastically deformed by heating so as to hermetically close the cavity mouth and/or the channel mouth, in such a way as to hermetically separate the optical cavity from the gas inflow channel.

Abstract: An atomic oscillator includes a semiconductor laser, an atomic cell, a light receiving element, a first temperature control element, and a second temperature control element. The semiconductor laser includes a first mirror layer, a second mirror layer, and an active layer disposed between the first mirror layer, the second mirror layer, and a heat transfer member disposed on the second mirror layer. The atomic cell is irradiated with light emitted from the semiconductor laser. In the atomic cell, an alkali metal atom is accommodated. The light receiving element detects intensity of light transmitted through the atomic cell and outputs a detection signal. The first temperature control element controls a temperature of the semiconductor laser. The second temperature control element is controlled based on the detection signal and is connected to the heat transfer member.

Abstract: An atomic oscillator includes a light source, a gas cell including an internal space in which an alkali metal atom is sealed, and a photodetector to detect light emitted from the light source and passing through the gas cell. A radiation region of the light source is wider than a sectional area of the internal space at a distal end of the gas cell relative to the light source.

Abstract: A chip scale atomic clock (CSAC) includes a temperature stabilized physics system and a temperature stabilized electronics circuitry electrically coupled to the temperature stabilized physics system. Atomic clocks utilize an optical signal having a frequency component. The temperature stabilization increases frequency stability. The temperature stabilized physics system includes a vapor cell and a magnetic field coil, and is enclosed in a magnetic shield. When an ambient temperature of a chip scale atomic clock increases, fluid is extended away, due to thermal expansion, from at least one reservoir towards or away from a thermally isolated subsystem in at least one of the temperature stabilized electronics circuitry and the temperature stabilized physics system.

Abstract: An atomic oscillator includes an atom cell that accommodates an alkali metal atom therein, a container that houses the atom cell, a substrate on which the container is disposed, and a thermally insulating mount that is fixed to the substrate and positions the container relative to the substrate.

Abstract: An atomic oscillator includes a light source unit including a light source and a first temperature control device controlling the light source to have a first temperature, an atom cell unit including an atom cell accommodating an alkali metal atom and that light emitted from the light source enters and a second temperature control device controlling the atom cell to have a second temperature different from the first temperature, and a container accommodating the light source unit and the atom cell unit and has a first surface and a second surface different from the first surface. The light source unit is mounted to the first surface, and an air gap is present between the light source unit and the second surface. The atom cell unit is mounted to the second surface, and an air gap is present between the atom cell unit and the first surface.

Abstract: An integrated microfabricated vapor cell sensor includes a transparent sensor cell body. The cell body has a cavity for a sensor fluid vapor which is covered by a first plate attached to the cell body. The sensor has a first signal path extending from a first signal emitter, through the cell body, through the cavity, through the cell body again, and to a first signal detector, and a second signal path extending through the cavity. The second signal path intersects the first signal path in the cavity. The second signal path may extend through the cell body, or may extend through the first plate. The signal emitters and signal detectors are located in the integrated microfabricated vapor cell sensor.

Abstract: A system for generating random noise includes a nanoscale magnetic device with two free ferromagnetic layers separated by a non-magnetic spacer layer. A current source directs a high current perpendicularly through the layers. The magnetic moments of the two free layers are excited by the spin transfer torque (STT) effect and continuously switch from a first direction to a second direction substantially antiparallel to said first direction with random transitions. The device output signal is a series of pulses with voltage peaks with random transition times between the peaks. The device output signal is input to a clipping circuit that cuts the signal off at certain voltage levels. A clocking circuit can sample the output of the clipping circuit to generate a random number.

Abstract: An integrated microfabricated sensor includes a sensor cell having a cell body, a first window attached to the cell body, and a second window attached to the cell body. The cell body laterally surrounds a cavity, so that both windows are exposed to the cavity. The sensor cell contains a sensor fluid material in the cavity. The cavity has concave profiles at cell body walls, so that the cavity is wider in a central region, approximately midway between the first window and the second window, than at the first surface and at the second surface. The cell body walls of the cell body have acute interior angles at both windows. The cell body is formed using an etch process that removes material from the cell body concurrently at the first surface and the second surface, forming the acute interior angles at both the first surface and the second surface.

Abstract: An atomic oscillator including a light source, a gas cell including an internal space in which alkali metal atoms are encapsulated, and a light detector that detects light which has emitted from the light source and has passed through the gas cell. The alkali metal atoms encapsulated in the internal space are adhered, in a liquid state or a solid state, to at least an incident window, such that light incident on the incident window is reduced.

Abstract: An atomic oscillator includes a semiconductor laser housed in a container, an atom cell housing alkali metal atoms and irradiated with a light output from the semiconductor laser, a light receiving element that detects an intensity of the light transmitted through the atom cell and outputs a detection signal, a temperature sensor housed in the container, a first temperature control element housed in the container and controlled based on output of the temperature sensor, and a second temperature control element housed in the container and controlled based on the detection signal. A distance between the second temperature control element and the semiconductor laser is smaller than a distance between the first temperature control element and the semiconductor laser.

Abstract: An atomic oscillator includes a semiconductor laser, an atomic cell, a light receiving element, a first temperature control element, a heat transfer member, and a second temperature control element. The laser includes a resonator and an insulation layer disposed around the resonator. The resonator includes a first mirror layer, a second mirror layer, and an active layer disposed between the first mirror layer and the second mirror layer. The atomic cell is irradiated with light emitted from the semiconductor laser. In the atomic cell, an alkali metal atom is accommodated. The light receiving element detects intensity of light transmitted through the atomic cell and outputs a detection signal. The first temperature control element controls a temperature of the semiconductor laser. The heat transfer member is disposed in the insulation layer. The second temperature control element is controlled based on the detection signal and is connected to the heat transfer member.

Abstract: An atomic oscillator includes: a light source; an atom cell containing a gaseous alkali metal atom, and a nitrogen- and argon-containing buffer gas, and through which light from the light source passes; a photodetector that detects light having passed through the atom cell; and a container containing only a mixed gas containing nitrogen and argon, and housing the atom cell.

Abstract: An optically pumped atomic clock includes an optically pumped atomic resonator provided with a vacuum-tight envelope equipped with optical interfaces and comprising, inside the vacuum-tight envelope a resonant cavity, optical mirrors, and caesium traps made of graphite, and outside the vacuum-tight envelope a vacuum pump, a magnetic shield, a magnetic field coil, an RF cable, a caesium oven, and an interface for connection with the caesium oven.

Abstract: The present invention relates to using spin transfer torque underneath a nanocontact on a magnetic thin film with perpendicular magnetic anisotropy (PMA), provides generation of dissipative magnetic droplet solitons and magnetic droplet-skyrmions and report on their rich dynamical properties. Micromagnetic simulations identify the conditions necessary to nucleate and drive droplet-skyrmions over a wide range of currents and fields. Micromagnetic simulations also demonstrate how droplets and droplet-skyrmions can be used as skyrmion injectors and detectors in skyrmion-based magnetic memories. The droplet-skyrmion can be controlled using both current and magnetic fields, and is expected to have applications in spintronics, magnonics, skyrmionics, and PMA-based domain-wall devices.

Abstract: An atomic clock system includes a magneto-optical trap (MOT) system that traps alkali metal atoms in a cell during a trapping stage of each of sequential coherent population trapping (CPT) cycles. The system also includes an interrogation system that generates an optical difference beam comprising a first optical beam having a first frequency and a second optical beam having a second frequency different from the first frequency. The interrogation system includes a direction controller that periodically alternates a direction of the optical difference beam through the cell during a CPT interrogation stage of each of the sequential clock measurement cycles to drive CPT interrogation of the trapped alkali metal atoms. The system also includes an oscillator system that adjusts a frequency of a local oscillator based on an optical response of the CPT interrogated alkali metal atoms during a state readout stage in each of the sequential clock measurement cycles.

Abstract: The present invention relates to a CPT atomic clock servo control SoC, which includes a microprocessor, a photoelectric signal demodulation functional module, a temperature control loop functional module, a laser and microwave loop control functional module, a C field control functional module, and a bus bridge. The bus bridge is connected to a system bus and a peripheral bus, for connecting to buses with different speeds. The photoelectric signal demodulation functional module extracts power change information of a microwave and a laser. The temperature control loop functional module controls temperatures of an absorption cell and a laser tube. The laser and microwave loop control functional module implements laser frequency locking and microwave loop locking. The C field control functional module provides a stable C field for the absorption cell.