Extending the coherence of a quantum dot hybrid qubit

Thorgrimsson, Brandur; Kim, Dohun; Yang, Yuan-Chi; Smith, L. W.; Simmons, C. B.; Ward, Daniel R.; Foote, Ryan H.; Corrigan, J.; Savage, D. E.; Lagally, M. G.; Friesen, Mark; Coppersmith, S. N.; Eriksson, M. A.

doi:10.1038/s41534-017-0034-2

Extending the coherence of a quantum dot hybrid qubit

Journal Article · Mon Aug 21 00:00:00 EDT 2017 · npj Quantum Information

DOI:https://doi.org/10.1038/s41534-017-0034-2· OSTI ID:1378088

Thorgrimsson, Brandur ^[1]; Kim, Dohun ^[2]; Yang, Yuan-Chi ^[3]; Smith, L. W. ^[3]; Simmons, C. B. ^[3]; Ward, Daniel R. ^[3]; Foote, Ryan H. ^[3]; Corrigan, J. ^[3]; Savage, D. E. ^[4]; Lagally, M. G. ^[4]; Friesen, Mark ^[3]; Coppersmith, S. N. ^[3]; Eriksson, M. A. ^[3]

Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Department of Physics, University of Wisconsin-Madison
Seoul National Univ. (Korea, Republic of). Dept. of Physics and Astronomy
Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics
Univ. of Wisconsin, Madison, WI (United States). Dept. of Materials Science and Engineering

Identifying and ameliorating dominant sources of decoherence are important steps in understanding and improving quantum systems. Here we show that the free induction decay time (T$$*\atop{2}$$) and the Rabi decay rate (Γ_Rabi) of the quantum dot hybrid qubit can be increased by more than an order of magnitude by appropriate tuning of the qubit parameters and operating points. Thus, by operating in the spin-like regime of this qubit, and choosing parameters that increase the qubit’s resilience to charge noise (which we show is presently the limiting noise source for this qubit), we achieve a Ramsey decay time T$$*\atop{2}$$ of 177 ns and a Rabi decay time 1/Γ_Rabi exceeding 1 µs. Furthermore, we find that the slowest Γ_Rabi is limited by fluctuations in the Rabi frequency induced by charge noise and not by fluctuations in the qubit energy itself.

View Accepted Manuscript (DOE)

Research Organization:: Univ. of Wisconsin, Madison, WI (United States)

Sponsoring Organization:: USDOE

Grant/Contract Number:: FG02-03ER46028

OSTI ID:: 1378088

Journal Information:: npj Quantum Information, Journal Name: npj Quantum Information Vol. 3; ISSN 2056-6387

Publisher:: Nature Partner JournalsCopyright Statement

Country of Publication:: United States

Language:: English

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