Low Temperature Physics: 35, 652 (2009); https://doi.org/10.1063/1.3224724 (10 pages)
Fizika Nizkikh Temperatur: Volume 35, Number 8-9 (August 2009), p. 829-840    ( to contents , go back )

Signal characteristics of charge-phase qubit-detector with parametric transformation of energy

V.I. Shnyrkov

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
E-mail: snyrkov@ilt.kharkov.ua

A.A. Soroka

National Science Center "Kharkov Institute of Physics and Technology", Akhiezer Institute for Theoretical Physics 1 Akademicheskaya Str., Kharkov 61108, Ukraine

W. Krech

Friedrich Schiller University, Institute of Solid State Physics, Helmholtzweg 5, D-07743 Jena, Germany
pos Анотація:

Received February 17, 2009

Abstract

Experimental analysis of the characteristics of the quantum partially coherent detector based on the charge-phase qubit coupled to a classical (wT < kBT/ħ) resonant circuit is carried out. It is shown that in an electromagnetic field the signal characteristics with a maximum coefficient of transformation appear when the effective quantum inductance of the qubit takes periodically (with Rabi-like frequency WRwT) positive and negative values. The reason of the effect of parametric transformation of energy (regeneration) in the qubit-detector with a periodic change of level population and its possible application in quantum informatics for registration of weak signals are discussed.

PACS: 42.50.Dv Nonclassical states of the electromagnetic field, including entangled photon states; quantum state engineering and measurements;
PACS: 74.25.Nf Response to electromagnetic fields (nuclear magnetic resonance, surface impedance, etc.);
PACS: 74.50.+r Tunneling phenomena; point contacts, weak links, Josephson effects;
PACS: 85.25.Am Superconducting device characterization, design, and modelling.

Key words: charge-phase qubit, detector, Rabi frequency, parametric regeneration, weak continuous measurements.

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