Microwavedriven coherent operation of a semiconductor quantum dot charge qubit
Abstract
An intuitive realization of a qubit is an electron charge at two welldefined positions of a double quantum dot. The qubit is simple and has the potential for highspeed operation because of its strong coupling to electric fields. But, charge noise also couples strongly to this qubit, resulting in rapid dephasing at all but one special operating point called the ‘sweet spot’. In previous studies d.c. voltage pulses have been used to manipulate semiconductor charge qubits but did not achieve highfidelity control, because d.c. gating requires excursions away from the sweet spot. Here, by using resonant a.c. microwave driving we achieve fast (greater than gigahertz) and universal single qubit rotations of a semiconductor charge qubit. The Zaxis rotations of the qubit are well protected at the sweet spot, and we demonstrate the same protection for rotations about arbitrary axes in the X–Y plane of the qubit Bloch sphere. We characterize the qubit operation using two tomographic approaches: standard process tomography and gate set tomography. Moreover, both methods consistently yield process fidelities greater than 86% with respect to a universal set of unitary singlequbit operations.
 Authors:
 Univ. of Wisconsin, Madison, WI (United States)
 Sandia National Lab. (SNLNM), Albuquerque, NM (United States)
 Publication Date:
 Research Org.:
 Sandia National Lab. (SNLNM), Albuquerque, NM (United States)
 Sponsoring Org.:
 USDOE National Nuclear Security Administration (NNSA)
 OSTI Identifier:
 1182978
 Report Number(s):
 SAND201415683J
Journal ID: ISSN 17483387; 533644
 Grant/Contract Number:
 AC0494AL85000
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Nature Nanotechnology
 Additional Journal Information:
 Journal Volume: 10; Journal Issue: 3; Journal ID: ISSN 17483387
 Publisher:
 Nature Publishing Group
 Country of Publication:
 United States
 Language:
 English
 Subject:
 77 NANOSCIENCE AND NANOTECHNOLOGY; quantum dots; quantum information; qubits
Citation Formats
Kim, Dohun, Ward, D. R., Simmons, C. B., Gamble, John King, BlumeKohout, Robin, Nielsen, Erik, Savage, D. E., Lagally, M. G., Friesen, Mark, Coppersmith, S. N., and Eriksson, M. A. Microwavedriven coherent operation of a semiconductor quantum dot charge qubit. United States: N. p., 2015.
Web. doi:10.1038/nnano.2014.336.
Kim, Dohun, Ward, D. R., Simmons, C. B., Gamble, John King, BlumeKohout, Robin, Nielsen, Erik, Savage, D. E., Lagally, M. G., Friesen, Mark, Coppersmith, S. N., & Eriksson, M. A. Microwavedriven coherent operation of a semiconductor quantum dot charge qubit. United States. doi:10.1038/nnano.2014.336.
Kim, Dohun, Ward, D. R., Simmons, C. B., Gamble, John King, BlumeKohout, Robin, Nielsen, Erik, Savage, D. E., Lagally, M. G., Friesen, Mark, Coppersmith, S. N., and Eriksson, M. A. 2015.
"Microwavedriven coherent operation of a semiconductor quantum dot charge qubit". United States.
doi:10.1038/nnano.2014.336. https://www.osti.gov/servlets/purl/1182978.
@article{osti_1182978,
title = {Microwavedriven coherent operation of a semiconductor quantum dot charge qubit},
author = {Kim, Dohun and Ward, D. R. and Simmons, C. B. and Gamble, John King and BlumeKohout, Robin and Nielsen, Erik and Savage, D. E. and Lagally, M. G. and Friesen, Mark and Coppersmith, S. N. and Eriksson, M. A.},
abstractNote = {An intuitive realization of a qubit is an electron charge at two welldefined positions of a double quantum dot. The qubit is simple and has the potential for highspeed operation because of its strong coupling to electric fields. But, charge noise also couples strongly to this qubit, resulting in rapid dephasing at all but one special operating point called the ‘sweet spot’. In previous studies d.c. voltage pulses have been used to manipulate semiconductor charge qubits but did not achieve highfidelity control, because d.c. gating requires excursions away from the sweet spot. Here, by using resonant a.c. microwave driving we achieve fast (greater than gigahertz) and universal single qubit rotations of a semiconductor charge qubit. The Zaxis rotations of the qubit are well protected at the sweet spot, and we demonstrate the same protection for rotations about arbitrary axes in the X–Y plane of the qubit Bloch sphere. We characterize the qubit operation using two tomographic approaches: standard process tomography and gate set tomography. Moreover, both methods consistently yield process fidelities greater than 86% with respect to a universal set of unitary singlequbit operations.},
doi = {10.1038/nnano.2014.336},
journal = {Nature Nanotechnology},
number = 3,
volume = 10,
place = {United States},
year = 2015,
month = 2
}
Web of Science

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