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: A modular quantum computer architecture is developed with a hierarchy of interactions that can scale to very large numbers of qubits. Local entangling quantum gates between qubit memories within a single modular register are accomplished using natural interactions between the qubits, and entanglement between separate modular registers is completed via a probabilistic photonic interface between qubits in different registers, even over large distances. This architecture is suitable for the implementation of complex quantum circuits utilizing the flexible connectivity provided by a reconfigurable photonic interconnect network. The subject architecture is made fault-tolerant which is a prerequisite for scalability.

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: Aspects of the present disclosure relate generally to systems and methods for use in the implementation and/or operation of quantum information processing (QIP) systems, and more particularly, to methods and systems for improving vacuum in compact room temperature packages. An exemplary method for preparing a vacuum chamber for a QIP system includes inserting, into a processing vacuum chamber, a lid having a shadow mask on an optical window, coating the inside of the lid with a getter material; removing the shadow mask from the optical window; and providing an ion trap package in the processing vacuum chamber and welding the lid on a top of the ion trap package to prepare the vacuum chamber.

Abstract: A package-level, integrated high-vacuum ion-chip enclosure having improved thermal characteristics is disclosed. Enclosures in accordance with the present invention include first and second chambers that are located on opposite sides of a chip carrier, where the chambers are fluidically coupled via a conduit through the chip carrier. The ion trap is located in the first chamber and disposed on the chip carrier. A source for generating an atomic flux is located in the second chamber. The separation of the source and ion trap in different chambers affords thermal isolation between them, while the conduit between the chambers enables the ion trap to receive the atomic flux.

Abstract: The disclosure describes various aspects of techniques for elliptical beam design using cylindrical optics that may be used in different applications, including in quantum information processing (QIP) systems. In an aspect, the disclosure describes an optical system having a first optical component having a first focal length, a second optical component having a second focal length and aligned with a first direction, and a third optical component having a third focal length and aligned with a second direction orthogonal to the first direction. The optical system is configured to receive one or more optical beams (e.g., circular or elliptical) and apply different magnifications in the first direction and the second direction to the one or more optical beams to image one or more elliptical Gaussian optical beams. A method for generating elliptical optical beams using a system as the one described above is also disclosed.

Abstract: The use of multiple ion chains in a single ion trap for quantum information processing (QIP) systems is described. Each chain can have its own set of laser beams with which to implement and operate quantum gates within that chain, where each chain may therefore correspond to a single quantum computing register or core. Operations can be performed in parallel across all of these chains as they can be treated independently from each other. To implement and operate quantum gates between different chains, neighboring chains are merged into a single, larger chain, in which one can perform quantum gates between any of the ions in the larger chain. The combined chains can then be separated again by another shuttling event as needed. To implement and operate quantum gates between ions which do not occupy neighboring chains, swap gates can be used via a sequence of intervening chains.

Abstract: Technologies for an optomechanical system include an intermediate plate having a top surface with multiple tapped holes arranged in a grid. A pair of dowel pin holes surround each tapped hole in a linear pattern. Multiple optical blocks are coupled to the intermediate plate using dowel pins positioned in the dowel pin holes and corresponding dowel pin holes defined in the bottom surface of the optical block. Each optical block includes multiple optical elements coupled to the top surface of the optical block with dowel pins. A cryostat may be coupled to the intermediate plate. A cryo-package assembly is mounted inside a cryo chamber of the cryostat. The cryo-package assembly includes a cryo device such as an ion trap covered by a machined copper lid. The lid includes a meandering passageway to allow for differential pumping in order to achieve ultra-high vacuum within the cryo-package assembly.

Abstract: Systems and methods for loading microfabricated ion traps are disclosed. Photo-ablation via an ablation pulse is used to generate a flow of atoms from a source material, where the flow is predominantly populated with neutral atoms. As the neutral atoms flow toward the ion trap, two-photon photo-ionization is used to selectively ionize a specific isotope contained in the atom flow. The velocity of the liberated atoms, atom-generation rate, and/or heat load of the source material is controlled by controlling the fluence of the ablation pulse to provide high ion-trapping probability while simultaneously mitigating generation of heat in the ion-trapping system that can preclude cryogenic operation. In some embodiments, the source material is held within an ablation oven comprising an electrically conductive housing that is configured to restrict the flow of agglomerated neutral atoms generated during photo-ablation toward the ion trap.

Abstract: The disclosure describes various aspects of techniques for elliptical beam design using cylindrical optics that may be used in different applications, including in quantum information processing (QIP) systems. In an aspect, the disclosure describes an optical system having a first optical component having a first focal length, a second optical component having a second focal length and aligned with a first direction, and a third optical component having a third focal length and aligned with a second direction orthogonal to the first direction. The optical system is configured to receive one or more optical beams (e.g., circular or elliptical) and apply different magnifications in the first direction and the second direction to the one or more optical beams to image one or more elliptical Gaussian optical beams. A method for generating elliptical optical beams using a system as the one described above is also disclosed.

Abstract: The disclosure describes various aspects of a practical implementation of multi-qubit gate architecture. A method is described that includes enabling ions in the ion trap having three energy levels, enabling a low-heating rate motional mode (e.g., zig-zag mode) at a ground state of motion with the ions in the ion trap; and performing a Cirac and Zoller (CZ) protocol using the low-heating rate motional mode as a motional state of the CZ protocol and one of the energy levels as an auxiliary state of the CZ protocol, where performing the CZ protocol includes implementing the multi-qubit gate. The method also includes performing one or more algorithms using the multi-qubit gate, including Grover's algorithm, Shor's factoring algorithm, quantum approximation optimization algorithm (QAOA), error correction algorithms, and quantum and Hamiltonian simulations. A corresponding system that supports the implementation of a multi-qubit gate architecture is also described.

Abstract: The disclosure describes various aspects of a practical implementation of multi-qubit gate architecture. A method is described that includes enabling ions in the ion trap having three energy levels, enabling a low-heating rate motional mode (e.g., zig-zag mode) at a ground state of motion with the ions in the ion trap; and performing a Cirac and Zoller (CZ) protocol using the low-heating rate motional mode as a motional state of the CZ protocol and one of the energy levels as an auxiliary state of the CZ protocol, where performing the CZ protocol includes implementing the multi-qubit gate. The method also includes performing one or more algorithms using the multi-qubit gate, including Grover's algorithm, Shor's factoring algorithm, quantum approximation optimization algorithm (QAOA), error correction algorithms, and quantum and Hamiltonian simulations. A corresponding system that supports the implementation of a multi-qubit gate architecture is also described.

Abstract: The disclosure describes various aspects of a software-defined quantum computer. For example, a method is described for generating an intermediate representation of source code for a software-defined quantum computer. The method includes performing a lexical analysis on a high-level intermediate representation of a quantum programming language; performing semantic analysis on an output of the lexical analysis; and generating a mid-level intermediate representation of the quantum programming language based on an output of the semantic analysis.

Abstract: The disclosure describes various aspects of a software-defined quantum computer. For example, a software-defined quantum computing architecture for allocating qubits is described that includes an application programming interface (API); a quantum operating system (OS) on which the API executes, with the quantum OS including a resource manager and a switch; and a plurality of quantum cores connected by the switch of the quantum resource OS. Moreover, the resource manager of the quantum resource OS determines an allocation of a plurality of qubits in the plurality of quantum cores.

Abstract: Aspects of the present disclosure describe techniques for independently controlling an angle (e.g., change in tilt) and/or position (e.g., change in lateral position) of an optical beam. For example, an optical beam control system may include a telescope with rotatable mirrors and lenses configured to provide a path to an optical beam to produce an output optical beam, which in turn is made into parallel optical beams following a diffractive optical element. The optical beam control system may also include a detector system to a beam angle and/or a beam position of one of the parallel optical beams to generate feedback signal or signals to control a rotation of one or more of the mirrors in the telescope such as to adjust the beam angle, the beam position, or both of the parallel optical beams. The optical beam control system may be part of a quantum information processing (QIP) system.

Abstract: The disclosure describes various aspects of a software-defined quantum computer. For example, a software-defined quantum computer and an expandable/modular quantum computer are described. Also described are at least a software-defined quantum architecture, a resource manager workflow, a quantum compiler architecture, hardware description language configuration, levels of application programming interface (API) access points, and exception handling in software-defined quantum architecture.

Abstract: An apparatus, method and system for resolving an n-number of photons from an optical source multiphoton event, the apparatus includes a cryostat includes a single-pixel superconducting nanowire single-photon detector (SNSPD) configured to receive an optical signal and therefrom produce a corresponding electrical signal, and a current bias source configured to supply a bias current to the SNSPD.

Abstract: Aspects of the present disclosure describe techniques that involve an active stabilization of coherent controllers using nearby qubits. In an aspect, a quantum information processing (QIP) system for stabilizing phase damping in qubits is described that provides a first and a second qubit ion, measuring magnetic field fluctuations using the second qubit ion, and generates one or more magnetic fields based on the measured magnetic field fluctuations, the one or more magnetic fields being applied near the first qubit ion to cancel the magnetic field fluctuations to stabilize the phase damping of the first qubit ion. Another such QIP system performs provides a first and a second qubit ion, locks a local oscillator to a frequency reference associated with the second qubit ion, and tracks, using the local oscillator, a frequency of the first qubit ion based on the frequency reference. Methods associated with these QIP systems are also described.

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: A modular quantum computer architecture is developed with a hierarchy of interactions that can scale to very large numbers of qubits. Local entangling quantum gates between qubit memories within a single modular register are accomplished using natural interactions between the qubits, and entanglement between separate modular registers is completed via a probabilistic photonic interface between qubits in different registers, even over large distances. This architecture is suitable for the implementation of complex quantum circuits utilizing the flexible connectivity provided by a reconfigurable photonic interconnect network. The subject architecture is made fault-tolerant which is a prerequisite for scalability.