A shuttling-based two-qubit logic gate for linking distant silicon quantum processors

Kavli Affiliate: Giordano Scappucci

| First 5 Authors: Akito Noiri, Kenta Takeda, Takashi Nakajima, Takashi Kobayashi, Amir Sammak

| Summary:

Control of entanglement between qubits at distant quantum processors using a
two-qubit gate is an essential function of a scalable, modular implementation
of quantum computation. Among the many qubit platforms, spin qubits in silicon
quantum dots are promising for large-scale integration along with their
nanofabrication capability. However, linking distant silicon quantum processors
is challenging as two-qubit gates in spin qubits typically utilize short-range
exchange coupling, which is only effective between nearest-neighbor quantum
dots. Here we overcome this problem by coupling spin qubits at distant quantum
processors via coherent spin shuttling and a two-qubit gate between them.
Coherent shuttling of a spin qubit enables efficient switching of the exchange
coupling with an on/off ratio exceeding 1,000, while preserving the spin
coherence by 99.6% for the single shuttling between neighboring dots. With this
shuttling-mode exchange control, we demonstrate a two-qubit controlled-phase
gate with a fidelity of 93%, assessed via randomized benchmarking. This result
shows a feasible path toward a quantum link between distant silicon quantum
processors, a key requirement for large-scale quantum computation.

| Search Query: ArXiv Query: search_query=au:”Giordano Scappucci”&id_list=&start=0&max_results=10

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