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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Information gain and loss for a quantum Maxwell's demon
AU - Naghiloo, M.
AU - Alonso, J. J.
AU - Romito, A.
AU - Lutz, E.
AU - Murch, K. W.
N1 - © 2018 American Physical Society
PY - 2018/7/17
Y1 - 2018/7/17
N2 - We use continuous weak measurements of a driven superconducting qubit to experimentally study the information dynamics of a quantum Maxwell's demon. We show how information gained by a demon who can track single quantum trajectories of the qubit can be converted into work using quantum coherent feedback. We verify the validity of a quantum fluctuation theorem with feedback by utilizing information obtained along single trajectories. We demonstrate, in particular, that quantum backaction can lead to a loss of information in imperfect measurements. We furthermore probe the transition between information gain and loss by varying the initial purity of the qubit.
AB - We use continuous weak measurements of a driven superconducting qubit to experimentally study the information dynamics of a quantum Maxwell's demon. We show how information gained by a demon who can track single quantum trajectories of the qubit can be converted into work using quantum coherent feedback. We verify the validity of a quantum fluctuation theorem with feedback by utilizing information obtained along single trajectories. We demonstrate, in particular, that quantum backaction can lead to a loss of information in imperfect measurements. We furthermore probe the transition between information gain and loss by varying the initial purity of the qubit.
KW - quant-ph
KW - cond-mat.mes-hall
KW - cond-mat.stat-mech
U2 - 10.1103/PhysRevLett.121.030604
DO - 10.1103/PhysRevLett.121.030604
M3 - Journal article
VL - 121
JO - Physical review letters
JF - Physical review letters
SN - 1079-7114
IS - 3
M1 - 030604
ER -