Shuttling-based trapped-ion quantum information processing

Abstract

Moving trapped-ion qubits in a microstructured array of radiofrequency traps offers a route towards realizing scalable quantum processing nodes. Establishing such nodes, providing sufficient functionality to represent a building block for emerging quantum technologies, e.g. a quantum computer or quantum repeater, remains a formidable technological challenge. In this review, we present a holistic view on such an architecture, including the relevant components, their characterization and their impact on the overall system performance. We present a hardware architecture based on a uniform linear segmented multilayer trap, controlled by a custom-made fast multi-channel arbitrary waveform generator. The latter allows for conducting a set of different ion shuttling operations at sufficient speed and quality. We describe the relevant parameters and performance specifications for microstructured ion traps, waveform generators and additional circuitry, along with suitable measurement schemes to verify the system performance. Furthermore, a set of different basic shuttling operations for dynamic qubit register reconfiguration is described and characterized in detail.arXiv:1912.04712v1 [quant-ph]

Crosstalk Suppression for Fault-tolerant Quantum Error Correction with Trapped Ions

“…However, all these crosstalk effects will be proportional to the already-small MS-gate error via an additional small parameter that scales with (ω j Ω) 2 1. Hence, to leading order, we can again consider the imperfect MS gate on the pair of active qubits (31), whereas the spectator qubits evolve coherently under the residual ac-Stark shifts (42), the strength of which may vary due to intensity fluctuations. Note that these systematic AC Stark shifts can be determined and experimentally compensated for by, e.g., adjusting the phases of all subsequent gates on the spectator ions.…”

“…After applying the desired sequence of operations, the ions can be split and shuttled back to the storage zones. There they remain as spectators of the operations on other active ions in the manipulation zones [8,10,[41][42][43][44][45]. Our study is motivated by new experimental capabilities that have recently emerged in the single-string trapped-ion modules.…”

Closed-loop optimization of fast trapped-ion shuttling with sub-quanta excitation

“…The earliest proposed architecture for scaling trapped ion systems relies on ion transport for connecting qubits and is known as the Quantum Charge Coupled Device (QCCD) architecture [4]. All transport primitives required for moving ions within the QCCD architecture (i.e., splitting, shuttling, merging and reordering) have been demonstrated in small systems [5][6][7][8][9][10][11][12].…”

A New Measurement Method for High Voltages Applied to an Ion Trap Generated by an RF Resonator

“…An ion trap is an essential physical platform in quantum information processing including quantum computing [ 1 , 2 , 3 , 4 , 5 ] and quantum networks [ 6 ], attributed to its high-fidelity quantum gates [ 7 , 8 ] and long coherence time [ 9 ]. Ions are confined by potentials created using electric fields, which allow fine control of various parameters of the potential [ 10 , 11 , 12 , 13 , 14 ]. To create sufficient potential to trap ions, a Paul trap requires strong oscillating electric fields that are generated by high voltages applied to the radio frequency (RF) electrode of the trap [ 15 ].…”

“…Gandolfi et al [ 16 ] proposed a method to infer the amplitude of RF voltages amplified by an RF resonator using a capacitive voltage divider. Johnson et al [ 10 ] proposed a method to stabilize RF voltages applied to the trap by measuring the voltage with a capacitive voltage divider installed inside a helical resonator, which has been used in many other experiments [ 11 , 12 , 13 ]. However, without proper shielding, the dividing ratio of practical capacitive voltage dividers is easily affected by environmental coupling.…”