Fundamental bounds on qubit reset
Basilewitsch D, Fischer J, Reich DM, Sugny D, Koch CP (2021)
Publication Type: Journal article
Publication year: 2021
Journal
Book Volume: 3
Article Number: 013110
Journal Issue: 1
DOI: 10.1103/PhysRevResearch.3.013110
Abstract
Qubit reset is a key task in the operation of quantum devices which, for many quantum hardware platforms, presently limits device clock speed. While it is known that coupling the qubit to an ancilla on demand allows for the fastest qubit reset, the limits on reset accuracy and speed due to the choice of ancilla have not yet been identified - despite the great flexibility in device design for most quantum hardware platforms. Here, we derive bounds on qubit reset in terms of maximum fidelity and minimum time, assuming control over the qubit and no control over the ancilla. For two-level ancillas, we find a provably time-optimal protocol which consists of purity exchange between qubit and ancilla brought into resonance. The globally minimal time can only be realized for specific choices of coupling and control which we identify. When increasing the size of the ancilla Hilbert space, the maximally achievable fidelity increases, whereas the reset time remains constant. Our results translate into device design principles for realizing, in a given quantum architecture, the fastest and most accurate protocol for qubit reset.
Involved external institutions
Germany (DE)
France (FR)How to cite
APA:
Basilewitsch, D., Fischer, J., Reich, D.M., Sugny, D., & Koch, C.P. (2021). Fundamental bounds on qubit reset. Physical Review Research, 3(1). https://dx.doi.org/10.1103/PhysRevResearch.3.013110
MLA:
Basilewitsch, Daniel, et al. "Fundamental bounds on qubit reset." Physical Review Research 3.1 (2021).
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