TY - JOUR
T1 - Measurement of purity, the simplest nonlinear functional of the density matrix
AU - Tanaka, Tohru
AU - Nakazato, Hiromichi
N1 - Funding Information:
The authors acknowledge inspiring discussions with Paolo Facchi, Giuseppe Florio, Vittorio Giovannetti, Saverio Pascazio, Kazuya Yuasa and Gen Kimura. This work is partly supported by a Grant-in-Aid for Scientific Research (C) from JSPS, Japan.
PY - 2014/6
Y1 - 2014/6
N2 - After reviewing the earlier ideas to measure the purity of a quantum system, a new scheme for the measurement of purity is presented, which aims at providing a simple, direct and efficient procedure without resorting to quantum state tomography. The scheme is also illustrated in the Bloch-vector representation for a two-level quantum system (qubit) and for a general D-level quantum system. As a variant, a simple example implemented in a one-dimensional scattering process to measure the purity of the target qubit is also given.
AB - After reviewing the earlier ideas to measure the purity of a quantum system, a new scheme for the measurement of purity is presented, which aims at providing a simple, direct and efficient procedure without resorting to quantum state tomography. The scheme is also illustrated in the Bloch-vector representation for a two-level quantum system (qubit) and for a general D-level quantum system. As a variant, a simple example implemented in a one-dimensional scattering process to measure the purity of the target qubit is also given.
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U2 - 10.1142/S1230161214400095
DO - 10.1142/S1230161214400095
M3 - Article
AN - SCOPUS:84898902344
VL - 21
JO - Open Systems and Information Dynamics
JF - Open Systems and Information Dynamics
SN - 1230-1612
IS - 1-2
M1 - 1440009
ER -