Information gain in tomography--a quantum signature of chaos.
We find quantum signatures of chaos in various metrics of information gain in quantum tomography. We employ a quantum state estimator based on weak collective measurements of an ensemble of identically prepared systems. The tomographic measurement record consists of a sequence of expectation values of a Hermitian operator that evolves under repeated application of the Floquet map of the quantum kicked top. We find an increase in information gain and, hence, higher fidelities in the reconstruction algorithm when the chaoticity parameter map increases. The results are well predicted by random matrix theory.
Center for Quantum Information and Control, University of New Mexico, Albuquerque, New Mexico 87131-0001, USA and Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada.
Vaibhav
V
Madhok
Center for Quantum Information and Control, University of New Mexico, Albuquerque, New Mexico 87131-0001, USA and Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
Carlos A
CA
Riofrío
Department of Physics and Computer Science, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada.
Shohini
S
Ghose
Center for Quantum Information and Control, University of New Mexico, Albuquerque, New Mexico 87131-0001, USA.
Ivan H
IH
Deutsch