Abstract: A method and system is provided for operating a quantum information processing (QIP) system, including a dual-space, single-species architecture for trapped-ion quantum information processing. An exemplary method of preparing the ions include i) applying a first optical beam to the plurality of ions to shelve at least a portion of the plurality of ions from a first state to a second state, ii) applying a second optical beam to the plurality of ions to deshelve the at least a portion of the plurality of ions from the second state to a third state, iii) applying a third optical beam to optically pump the at least a portion of the plurality of ions from the third state and to a fourth state, and iv) iteratively repeat i) to iii) to transition a remaining portion of the plurality of ions to the fourth state.

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 a fast single-mode spectroscopy technique that may be used in trapped-ion QIP systems. A method is described that includes performing a first measurement scan (full scan) across all motional modes of an ion chain in a trap followed by a second measurement scan on a single motional mode of the motional modes (single-mode scan). The second measurement scan determines a frequency shift associated with the single motional mode, which is applied to adjust the frequencies of all the motional modes. An implementation of two-qubit gates for quantum computations is based on the adjusted frequencies. A quantum computer or QIP system is also described that is configured to implement and perform the method described above.

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 system and method is provided for use in the implementation and/or operation of quantum information processing (QIP) systems, and more particularly, to design or configure an optimal side-band cooling operation for trapped ions. A method is described that involves applying a first cooling operation on the trapped ion chain and subsequently applying a second cooling operation on the trapped ion chain that includes applying to each cooling ion in the trapped ion chain, as part of a side-band cooling pulse sequence, at least one analysis pulse followed by a corresponding batch with one or more side-band cooling pulses, wherein each analysis pulse is configured to determine a detuning and pulse duration of the one or more side-band cooling pulses of the corresponding batch. A quantum computer or QIP system is also described that enables the operation of the method described above.

Abstract: In an ion trap chip, an RF electrode for producing a radio-frequency ion-trapping electric field is formed in one of a plurality of metallization layers formed on a substrate and separated from each other by intermetal dielectric. At least two spans of the RF electrode are suspended between support pillars over a void defined within one or more layers of intermetal dielectric. For each span that is suspended between a first and a second support pillar, an area ATotal and an area ASupported are defined. ATotal is the total electrode area from an initial edge of the first support pillar to an initial edge of the second support pillar. ASupported is the electrode area directly underlain by the first support pillar. In each span that is suspended from a first support pillar to a second support pillar, ASupported is not more than one-half of ATotal.

Abstract: A radio-frequency (RF) surface ion trap chip includes an RF electrode and an integrated capacitive voltage divider in which an intermediate voltage node is capacitively connected between the RF electrode and a ground. A sensor output trace is connected to the intermediate voltage node.

Abstract: An ion trap chip, which may be used for quantum information processing and the like, includes an integrated microwave antenna. The antenna is formed as a radiator connected by one of its ends to the center trace of a microwave transmission line and connected by its other end to a current return path through a ground trace of the microwave transmission line. The radiator includes several parallel, coplanar radiator traces connected in series. The radiator traces are connected such that they all carry electric current in the same direction, so that collectively, they simulate a single, unidirectionally flowing sheet of current. In embodiments, induced currents in underlying metallization planes are suppressed by parallel slots that extend in a direction perpendicular to the radiator traces.

Abstract: A platform for trapping atomic ions includes a substrate and a plurality of metallization layers that overlie the substrate. The metallization layer farthest from the substrate is a top layer patterned with electrostatic control trap electrodes and radio-frequency trap electrodes. Another metallization layer is a microwave layer patterned to define a microwave circuit. The microwave layer lies below the top layer. The microwave circuit is adapted to generate, in use, a microwave magnetic field above the electrostatic control and radio-frequency trap electrodes. The top metallization layer includes slots that, in use, are penetrated by microwave energy from the microwave circuit.