Abstract: A method of performing a quantum operation performed on a quantum device comprising at least one pair of quantum qubit crystals, the method comprising: setting a detuning value of each qubit crystal to a first value, wherein the detuning value is a difference between a frequency of a gate field of the at least one pair of qubit crystals and a frequency of a motional mode of the at least one pair of qubit crystals; ramping down the detuning value according to a ramping function such that the detuning value is decreased from the first value to a second value; ramping up the detuning value according to the ramping function such that the detuning value is increased from the second value to a third value; wherein the detuning value is changed by changing the frequency of the gate field and/or the frequency of the motional mode.

Abstract: A controller of an atomic system controls voltage sources to cause first and second atomic objects of an object crystal to experience a coupling force. The object crystal is confined at a target location of a confinement apparatus that defines an axis thereat. The coupling force includes a component that is perpendicular to the axis. The controller causes the voltage sources to generate voltage signals that cause the object crystal to experience an axial confinement corresponding to a transition region for selected motional modes of the object crystal. When the atomic objects experience the coupling force and the object crystal experiences the axial confinement corresponding to the transition region, the selected motional modes form mixed motional modes. The controller causes manipulation sources to generate manipulation signals that are incident on the target location and that address the mixed motional modes to cause an entangling interaction between the atomic objects.

Abstract: A controller causes performance of a shelving operation by causing a manipulation source to provide a manipulation signal characterized by a frequency and amplitude. The frequency is detuned from a transition frequency corresponding to a transition between a first quantum state and second quantum state of a quantum object. The detuning is an initial detuning and the amplitude is an initial amplitude. The manipulation signal is incident on the quantum object. The controller controls operation of the manipulation source to cause the detuning of the manipulation signal to evolve from the initial detuning to a zero detuning and the amplitude to increase from the initial amplitude to a maximum amplitude. The controller then controls operation of the manipulation source to cause the detuning of the manipulation signal to evolve from the zero detuning to a final detuning and the amplitude to decrease from the maximum amplitude to a final amplitude.

Abstract: A confinement apparatus confines quantum objects and includes a magnetic field control circuit (MFCC) associated with a defined location of the confinement apparatus. Passive dynamical decoupling of magnetic field sensitive sublevels is performed on a quantum object disposed at the defined location by controlling current provided to the MFCC to cause the MFCC to generate an applied magnetic field at the defined location that is aligned with a static quantization field associated with the confinement apparatus and that has an amplitude that is larger than an amplitude of the static quantization field; and controlling the current provided to the MFCC to cause the applied magnetic field to rotate such that an experienced quantization field experienced by the quantum object at the defined location rotates. An angular velocity of the rotation of the experienced quantization field is <2? times a frequency difference between adjacent hyperfine sublevels of the quantum object.

Abstract: A quantum logic spectroscopy system for an ion trap configured to trap a primary ion and a detection ion, the quantum logic spectroscopy system configured to apply one or more conditioning operations, each of the one or more conditioning operations comprising applying a mapping operation to map a primary ion state of the primary ion on to a detection ion state of the detection ion, applying a state change operation comprising changing the detection ion state if the detection ion state has a first detection state value, and determine a probability of the detection ion state changing in response to the application of the state change operation, and determine the primary ion state using the determined probability or determine that the primary ion state is indeterminate using the determined probability.

Abstract: A controller of a quantum system causes performance of a single qubit gate on a target qubit. The controller causes a dressing field circuit to generate a dressing field at a target location where the target qubit is located. The dressing field modifies a set of initial states into a set of superposition states. A first (second) dressed state of the set of superposition states includes a non-zero contribution from a first (second) qubit state of the set of initial states. A dressed frequency difference between the first and second dressed states and a qubit frequency difference between the first and second qubit states are different. The controller causes a gate microwave signal characterized by the dressed frequency difference plus the qubit frequency difference to be incident on the target location. After a gate time, the controller controls operation of the dressing field circuit to stop generating the dressing field.

Abstract: A controller of a quantum system causes a dressing field circuit to generate a dressing field at a target location where one or more target qubits are located. The dressing field modifies a set of initial states into a set of superposition states. A first (second) dressed state of the set of superposition states includes a non-zero contribution from a first (second) qubit state of the set of initial states. A dressed frequency difference between the first and second dressed states and a qubit frequency difference between the first and second qubit states are different. The dressing field is configured to generate first and second dressed states having a desired level of sensitivity (e.g., energy/frequency dependence) on the component of the external magnetic field that is in the quantization direction of the quantum system.

Abstract: A method for laser cooling an object crystal comprising at least two atomic objects and confined by a confinement apparatus is provided. A controller controls one or more manipulation sources to cause a first instance of manipulation signals to be incident on the object crystal at a target location defined at least in part by the confinement apparatus. The manipulation signals are configured to laser cool a first motional mode of the object crystal. The controller causes an adiabatic transfer of phonons from a second motional mode of the object crystal to the first motional mode of the object crystal. The controller controls the one or more manipulation sources to cause a second instance of the manipulation signals to be incident on the object crystal at the target location. The manipulation signals are configured to laser cool the first motional mode of the object crystal.

Abstract: An atomic object confinement apparatus comprising a plurality of electrodes and one or more quasi-direct-current (quasi-DC) circuits. The plurality of electrodes comprise a plurality of radio frequency (RF) rail electrodes arranged to define, at least in part, a periodic array of confinement segments. The plurality of RF rail electrodes are configured such that, when an oscillating voltage signal is applied thereto, the plurality of RF rail electrodes generate a pseudopotential in a form of an array of trapping regions configured to contain at least one atomic object within a respective trapping region of the array of trapping regions. The one or more quasi-direct-current (quasi-DC) circuits are arranged to generate a magnetic field having a selectable magnitude and a selectable direction, such that the generated magnetic field acts on at least one atomic object within the array of trapping regions.

Abstract: A controller of a quantum system causes a geometric phase gate to be performed on two or more qubits by causing two or more qubits of the quantum system to experience a (near field and/or non-radiating) magnetic field gradient; and, responsive to determining that a gate time period has elapsed since the two or more qubits of the quantum system started to experience the magnetic field gradient, causing the two or more qubits to no longer experience the magnetic field gradient. The entanglement of the two or more qubits corresponding to the performance of the gate is enacted, mediated, and/or caused by the magnetic field gradient.

Abstract: A trapped-ion quantum logic gate and a method of operating the trapped-ion quantum logic gate are provided. The trapped-ion quantum logic gate includes at least one ion having two internal states and forming a qubit having a qubit transition frequency ?0, a magnetic field gradient, and two microwave fields. Each of the two microwave fields has a respective frequency that is detuned from the qubit transition frequency ?0 by frequency difference ?. The at least one ion has a Rabi frequency ?? due to the two microwave fields and a Rabi frequency ?g due to the magnetic field gradient. The method includes applying the magnetic field gradient and the two microwave fields to the at least one ion such that a quantity ?g/? is in a range between zero and 5×10?2.

Abstract: A trapped-ion quantum logic gate and a method of operating the trapped-ion quantum logic gate are provided. The trapped-ion quantum logic gate includes at least one ion having two internal states and forming a qubit having a qubit transition frequency ?0, a magnetic field gradient, and two microwave fields. Each of the two microwave fields has a respective frequency that is detuned from the qubit transition frequency ?0 by frequency difference ?. The at least one ion has a Rabi frequency ?? due to the two microwave fields and a Rabi frequency ?g due to the magnetic field gradient. The method includes applying the magnetic field gradient and the two microwave fields to the at least one ion such that a quantity ?g/? is in a range between zero and 5×10?2.