TY - JOUR
T1 - Squeezing with a flux-driven Josephson parametric amplifier
AU - Zhong, L.
AU - Menzel, E.P.
AU - Di Candia, R.
AU - Eder, P.
AU - Ihmig, M.
AU - Baust, A.
AU - Haeberlein, M.
AU - Hoffmann, E.
AU - Inomata, K.
AU - Yamamoto, T.
AU - Nakamura, Y.
AU - Solano, Enrique
AU - Deppe, F.
AU - Marx, A.
AU - Gross, R.
PY - 2013
Y1 - 2013
N2 - Josephson parametric amplifiers (JPA) are promising devices for applications in circuit quantum electrodynamics and for studies on propagating quantum microwaves because of their good noise performance. In this work, we present a systematic characterization of a flux-driven JPA at millikelvin temperatures. In particular, we study in detail its squeezing properties by two different detection techniques. With the homodyne setup, we observe the squeezing of vacuum fluctuations by superposing signal and idler bands. For a quantitative analysis, we apply dual-path cross-correlation techniques to reconstruct the Wigner functions of various squeezed vacuum and thermal states. At 10 dB signal gain, we find 4.9 ± 0.2 dB squeezing below the vacuum. In addition, we discuss the physics behind squeezed coherent microwave fields. Finally, we analyze the JPA noise temperature in the degenerate mode and find a value smaller than the standard quantum limit for phase-insensitive amplifiers.
AB - Josephson parametric amplifiers (JPA) are promising devices for applications in circuit quantum electrodynamics and for studies on propagating quantum microwaves because of their good noise performance. In this work, we present a systematic characterization of a flux-driven JPA at millikelvin temperatures. In particular, we study in detail its squeezing properties by two different detection techniques. With the homodyne setup, we observe the squeezing of vacuum fluctuations by superposing signal and idler bands. For a quantitative analysis, we apply dual-path cross-correlation techniques to reconstruct the Wigner functions of various squeezed vacuum and thermal states. At 10 dB signal gain, we find 4.9 ± 0.2 dB squeezing below the vacuum. In addition, we discuss the physics behind squeezed coherent microwave fields. Finally, we analyze the JPA noise temperature in the degenerate mode and find a value smaller than the standard quantum limit for phase-insensitive amplifiers.
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84890414918&partnerID=MN8TOARS
U2 - 10.1088/1367-2630/15/12/125013
DO - 10.1088/1367-2630/15/12/125013
M3 - Article
SN - 1367-2630
VL - 15
JO - New Journal of Physics
JF - New Journal of Physics
ER -