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arXiv · 2009.08469

Protecting Quantum Information in Quantum Dot Spin Chains by Driving Exchange Interactions Periodically

John S. Van Dyke·Yadav P. Kandel·Haifeng Qiao·John M. Nichol·Sophia E. Economou·Edwin Barnes
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Abstract

Recent work has demonstrated a new route to discrete time crystal physics in quantum spin chains by periodically driving nearest-neighbor exchange interactions in gate-defined quantum dot arrays [arXiv:2006.10913]. Here, we present a detailed analysis of exchange-driven Floquet physics in small arrays of GaAs quantum dots, including phase diagrams and additional diagnostics. We also show that emergent time-crystalline behavior can benefit the protection and manipulation of multi-spin states. For typical levels of nuclear spin noise in GaAs, the combination of driving and interactions protects spin-singlet states beyond what is possible in the absence of exchange interactions. We further show how to construct a time-crystal-inspired CZ gate between singlet-triplet qubits with high fidelity. These results show that periodically driving exchange couplings can enhance the performance of quantum dot spin systems for quantum information applications.

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John S. Van Dyke, Yadav P. Kandel, Haifeng Qiao, John M. Nichol, Sophia E. Economou, Edwin Barnes. 2020-09-17. Protecting Quantum Information in Quantum Dot Spin Chains by Driving Exchange Interactions Periodically. https://doi.org/10.1103/physrevb.103.245303

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