Noise-resistant Landau-Zener sweeps from geometrical curves

Journal Article · 02 February 2022 · Quantum

DOI: https://doi.org/10.22331/q-2022-02-02-639 · OSTI ID:1843299

Zhuang, Fei ^[1]; Zeng, Junkai ^[2]; Economou, Sophia E. ^[1]; Barnes, Edwin ^[1]

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1. Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
2. Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA, Shenzhen Institute of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China

Landau-Zener physics is often exploited to generate quantum logic gates and to perform state initialization and readout. The quality of these operations can be degraded by noise fluctuations in the energy gap at the avoided crossing. We leverage a recently discovered correspondence between qubit evolution and space curves in three dimensions to design noise-robust Landau-Zener sweeps through an avoided crossing. In the case where the avoided crossing is purely noise-induced, we prove that operations based on monotonic sweeps cannot be robust to noise. Hence, we design families of phase gates based on non-monotonic drives that are error-robust up to second order. In the general case where there is an avoided crossing even in the absence of noise, we present a general technique for designing robust driving protocols that takes advantage of a relationship between the Landau-Zener problem and space curves of constant torsion.

• Research Organization: Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
• Sponsoring Organization: US Department of the Navy, Office of Naval Research (ONR); USDOE; USDOE Office of Science (SC)
• Grant/Contract Number: SC0018326
• OSTI ID: 1843299
• Journal Information: Quantum, Journal Name: Quantum Vol. 6; ISSN 2521-327X
• Publisher: Verein zur Forderung des Open Access Publizierens in den QuantenwissenschaftenCopyright Statement
• Country of Publication: Austria
• Language: English