Abstract: Aspects of the present disclosure describe techniques for mitigating charging on optical windows. For example, a device for mitigating charges inside a chamber of a trapped ion system is described that includes an array of parallel wires formed from a single, conductive plate by cutting elongated gaps through an entire thickness of the conductive plate that separate the wires, an outer portion of the conductive plate to which the wires are attached is configured to position the wires to run parallel to one or more trapped ions in the chamber and to position the wires between a dielectric component of the chamber and the one or more trapped ions. A chamber with such an array of parallel wires and a method of using such an array of parallel wires are also described.

Abstract: The disclosure describes various aspects of techniques for cooling a chain of ions to near the combined ground state that does not grow with the number of ions in the chain. By addressing each ion individually and using each ion to cool a different motional mode, it is possible to cool the motional modes concurrently. In an example, a third of the total motional modes can be cooled at the same time. In an aspect, the techniques include generating a sideband cooling laser beam for each ion in the ion chain, concurrently cooling two or more motional modes associated with the ions in the ion chain using the respective sideband cooling laser beam until each of the two or more motional modes reaches a motional ground state, and performing a quantum computation using the ion chain after the two or more motional modes have reached the motional ground state.

Abstract: Aspects of the present disclosure describe techniques for measuring collision rate with spatial filtering of scattered light. For example, a method for characterizing vacuum in a chamber is described that includes generating, inside the chamber, a potential well having a single, shallow potential region within which an ion is trapped, the shallow potential region having a lowest potential of the potential well, optically monitoring the ion within the potential well, detecting, based on the optically monitoring, a movement of the ion away from the shallow potential region in response to a collision with a background gas, and determining a pressure inside the chamber based on a rate of detected movements of the ion.

Abstract: The disclosure describes various aspects of a vibrationally isolated cryogenic shield for local high-quality vacuum. More specifically, the disclosure describes a cryogenic vacuum system replicated in a small volume in a mostly room temperature ultra-high vacuum (UHV) system by capping the volume with a suspended cryogenic cold finger coated with a high surface area sorption material to produce a localized extreme high vacuum (XHV) or near-XHV region. The system is designed to ensure that all paths from outgassing materials to the control volume, including multiple bounce paths off other warm surfaces, require at least one bounce off of the high surface area sorption material on the cold finger. The outgassing materials can therefore be pumped before reaching the control volume. To minimize vibrations, the cold finger is only loosely, mechanically connected to the rest of the chamber, and the isolated along with the cryogenic system via soft vacuum bellows.

Abstract: Aspects of the present disclosure describe techniques for cooling motional states in an ion trap for quantum computers. In an aspect, a method includes performing Doppler cooling and sideband cooling to sweep motional states associated with a motional mode to a zero motional state; applying a gate interaction on a red sideband; detecting, a population of non-zero motional states of the motional mode that remains after performing the Doppler cooling and the sideband cooling; and removing at least part of the population. In another aspect, a method includes performing a Doppler cooling; applying a gate interaction on a red sideband; detecting whether a population of non-zero motional states of the motional mode remains after performing the Doppler cooling; and redistributing the population of the non-zero motional states by Doppler cooling when a population is detected. A quantum information processing (QIP) system that performs these methods is also described.

Abstract: Aspects of a vibrationally isolated cryogenic shield for local high-quality vacuum are described. More specifically, a cryogenic vacuum system is described that is replicated in a small volume in a mostly room temperature ultra-high vacuum (UHV) system by capping the volume with a suspended cryogenic cold finger coated with a high surface area sorption material to produce a localized extreme high vacuum (XHV) or near-XHV region. The system ensures that paths from outgassing materials to the control volume, including bounce paths off other warm surfaces, require at least one bounce off of the high surface area sorption material on the cold finger. The outgassing materials can be pumped before reaching the control volume. To minimize vibrations, the cold finger is only loosely, mechanically connected to the rest of the chamber, and isolated along with the cryogenic system via soft vacuum bellows.

Abstract: Aspects of the present disclosure describe techniques for using a parabolic Cassegrain-type reflector for ablation. For example, a system for ablation loading of a trap is described that includes a reflector having a hole aligned with a loading aperture of the trap, and an atomic source positioned at a focal point of the reflector, where one or more laser beams are reflected from a reflective front side of the reflector and focused on a surface of the atomic source to produce an atomic plume, and the atomic plume once produced passing through the hole in the reflector and through a loading aperture of the trap for loading the trap. A method for ablation loading of a trap within a chamber in a trapped ion system is also described.

Abstract: The disclosure describes various aspects of different techniques for flexible touch sensors and method for wide-field imaging of an atom or ion trap. A touch sensor is described for controlling movement of a control element for use with the trap that includes an outer structure and an inner structure that holds the control element and moves within the outer structure. The trap is inside an ultra-high vacuum (UHV) environment and the outer and inner structures are outside the UHV environment and separated by a UHV window. The control element or elements are brought into proximity of the UHV window in connection with controlling targets at the trap. The inner structure can stop moving within the outer structure to avoid damaging of the UHV window with the control element(s) in response to the inner structure being in physical contact with or within a set proximity of the outer structure.

Abstract: Aspects of the present disclosure describe an atomic oven including a cathode, an anode that comprises a source material, and a power supply that provides a voltage between the cathode and the anode, wherein applying the voltage causes multiple electrons from the cathode to ablate the source material from the anode or locally heat the anode to cause source material to evaporate from the anode and, in both case, to produce a stream of ablated or evaporated particles that passes through an opening in the cathode.

Abstract: The disclosure describes various aspects of a shed-resistant thermal atom source. More specifically, a thermal atom source is described for uniform thermal flux of target atomic species in which a metal wadding material is used as an intermediary surface for sublimation of the atoms, preventing the source material from shedding or dropping. In an aspect, a thermal atom source may include a container with closed and open ends, and inside a source material near the closed end and a wadding between the source material and the open end; a heater coupled to the closed end; one or more clamps configured to secure the container and the heater; and a current source coupled to the container and the heater to cause a temperature to increase such that a portion of the source material is released and diffuses to the open end through the wadding prior to being emitted as a flux.

Abstract: The disclosure describes various aspects of acousto-optic modulator (AOM) configurations for quantum processing. A method is described including generating, by a first AOM from a laser beam, first and second diffracted laser beams at different angles based on first and second radio frequency (RF) tones. An optical component focuses the diffracted laser beams onto a second AOM, which generates third and fourth diffracted laser beams based on the first RF tone and a third RF tone and the second RF tone and a fourth RF tone respectively, wherein the third and fourth diffracted laser beams are substantially parallel when incident on a respective ion in a chain of ions in a trap. Quantum information in the ion is controlled to perform quantum processing based on the third and fourth diffracted laser beams. Another method is described including generating, by an AOM, a small polarization rotation of an undiffracted laser beam.

Abstract: The disclosure describes various aspects of techniques that can be used for making hermetic feedthroughs for enclosures. For example, a panel that provides a hermetic seal to a system enclosure can include an enclosure board made of a printed circuit board (PCB) and configured to have a size and shape that precisely covers an access to the system enclosure, the enclosure board including multiple inner connectors on an inner side of the PCB facing the inside of the system enclosure and multiple outer connectors on an outer side of the PCB facing the outside the system enclosure for feeding one or more of signals or fluids (e.g., gases, liquids, vacuum) through the PCB by having inner and outer connectors connected through the PCB. The panel may further include a gasket fitting the size and shape of the enclosure board and used with the enclosure board to provide the hermetic seal.

Abstract: The disclosure describes various aspects of a system with scalable and programmable coherent waveform generators. A network and digital-to-analog conversion (DAC) cards used by the network are described where each DAC card has a clock divider/replicator device with an input SYNC pin, a digital logic component, and one or more DAC components, and each output of the DAC components is used to control optical beams for a separate qubit of a quantum information processing (QIP) system. The network also includes a first distribution network to provide a clock signal to the clock divider/replicator device in the DAC cards, and a second distribution network to provide a start signal to the DAC cards, where the start signal is used by the digital logic component in the DAC card to assert the input SYNC pin when the start signal is asserted unless it is masked by the digital logic component.

Abstract: Aspects of the present disclosure describe techniques for mitigating charging on optical windows. For example, a device for mitigating charges inside a chamber of a trapped ion system is described that includes an array of parallel wires formed from a single, conductive plate by cutting elongated gaps through an entire thickness of the conductive plate that separate the wires, an outer portion of the conductive plate to which the wires are attached is configured to position the wires to run parallel to one or more trapped ions in the chamber and to position the wires between a dielectric component of the chamber and the one or more trapped ions. A chamber with such an array of parallel wires and a method of using such an array of parallel wires are also described.

Abstract: The disclosure describes various aspects of different techniques for flexible touch sensors and method for wide-field imaging of an atom or ion trap. A touch sensor is described for controlling movement of a control element for use with the trap that includes an outer structure and an inner structure that holds the control element and moves within the outer structure. The trap is inside an ultra-high vacuum (UHV) environment and the outer and inner structures are outside the UHV environment and separated by a UHV window. The control element or elements are brought into proximity of the UHV window in connection with controlling targets at the trap. The inner structure can stop moving within the outer structure to avoid damaging of the UHV window with the control element(s) in response to the inner structure being in physical contact with or within a set proximity of the outer structure.

Abstract: The disclosure describes various aspects of techniques that can be used for making hermetic feedthroughs for enclosures. For example, a panel that provides a hermetic seal to a system enclosure can include an enclosure board made of a printed circuit board (PCB) and configured to have a size and shape that precisely covers an access to the system enclosure, the enclosure board including multiple inner connectors on an inner side of the PCB facing the inside of the system enclosure and multiple outer connectors on an outer side of the PCB facing the outside the system enclosure for feeding one or more of signals or fluids (e.g., gases, liquids, vacuum) through the PCB by having inner and outer connectors connected through the PCB. The panel may further include a gasket fitting the size and shape of the enclosure board and used with the enclosure board to provide the hermetic seal.

Abstract: The disclosure describes various aspects of acousto-optic modulator (AOM) configurations for quantum processing. A method is described including generating, by a first AOM from a laser beam, first and second diffracted laser beams at different angles based on first and second radio frequency (RF) tones. An optical component focuses the diffracted laser beams onto a second AOM, which generates third and fourth diffracted laser beams based on the first RF tone and a third RF tone and the second RF tone and a fourth RF tone respectively, wherein the third and fourth diffracted laser beams are substantially parallel when incident on a respective ion in a chain of ions in a trap. Quantum information in the ion is controlled to perform quantum processing based on the third and fourth diffracted laser beams. Another method is described including generating, by an AOM, a small polarization rotation of an undiffracted laser beam.

Abstract: The disclosure describes various aspects of techniques for cooling a chain of ions to near the combined ground state that does not grow with the number of ions in the chain. By addressing each ion individually and using each ion to cool a different motional mode, it is possible to cool the motional modes concurrently. In an example, a third of the total motional modes can be cooled at the same time. In an aspect, the techniques include generating a sideband cooling laser beam for each ion in the ion chain, concurrently cooling two or more motional modes associated with the ions in the ion chain using the respective sideband cooling laser beam until each of the two or more motional modes reaches a motional ground state, and performing a quantum computation using the ion chain after the two or more motional modes have reached the motional ground state.

Abstract: The disclosure describes various aspects of a vibrationally isolated cryogenic shield for local high-quality vacuum. More specifically, the disclosure describes a cryogenic vacuum system replicated in a small volume in a mostly room temperature ultra-high vacuum (UHV) system by capping the volume with a suspended cryogenic cold finger coated with a high surface area sorption material to produce a localized extreme high vacuum (XHV) or near-XHV region. The system is designed to ensure that all paths from outgassing materials to the control volume, including multiple bounce paths off other warm surfaces, require at least one bounce off of the high surface area sorption material on the cold finger. The outgassing materials can therefore be pumped before reaching the control volume. To minimize vibrations, the cold finger is only loosely, mechanically connected to the rest of the chamber, and the isolated along with the cryogenic system via soft vacuum bellows.

Abstract: The disclosure describes various aspects of a shed-resistant thermal atom source. More specifically, a thermal atom source is described for uniform thermal flux of target atomic species in which a metal wadding material is used as an intermediary surface for sublimation of the atoms, preventing the source material from shedding or dropping. In an aspect, a thermal atom source may include a container with closed and open ends, and inside a source material near the closed end and a wadding between the source material and the open end; a heater coupled to the closed end; one or more clamps configured to secure the container and the heater; and a current source coupled to the container and the heater to cause a temperature to increase such that a portion of the source material is released and diffuses to the open end through the wadding prior to being emitted as a flux.