High quality exchange rotations in spin qubits using symmetric gating
ORAL
Abstract
We present results on a singlet-triplet qubit implemented in a GaAs/AlGaAs heterostructure and we show that exchange oscillations can be realized either by tilting the double well potential, the conventional method, or by symmetrically lowering the barrier, as originally suggested by Loss and DiVincenzo. The two methods are compared here. We find that lowering the barrier between dots has much less relative exchange noise compared to tilting the potential. Since exchange rotations are sensitive to electrical noise and relatively insensitive to nuclear noise, this yields significantly enhanced free induction decay times and quality factors. Our results are comparable to those reported recently in silicon quantum dot devices, obtained using similar techniques.
*Support through IARPA-MQCO, LPS-MPO-CMTC, Army Research Office, and the Danish National Research Foundation is acknowledged
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Authors
F. Martins
IMCN/NAPS, Univ. catholique de Louvain, Belgium
Center for quantum devices, Niels Bohr Institute, University of Copenhagen, Denmark
F. K. Malinowski
Center for quantum devices, Niels Bohr Institute, University of Copenhagen, Denmark
P. D. Nissen
Center for quantum devices, Niels Bohr Institute, University of Copenhagen, Denmark
C. M. Marcus
Center for quantum devices, Niels Bohr Institute, University of Copenhagen, Denmark
F. Kuemmeth
Center for quantum devices, Niels Bohr Institute, University of Copenhagen, Denmark
E. Barnes
Department of Physics, Virginia Tech / Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, USA
G. C. Gardner
Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University, USA
S. Fallahi
Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University, USA
M. J. Manfra
Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University, USA
