Coherent dynamics of a Josephson charge qubit

被引：148

作者：

Duty, T ^{[1
]}

Gunnarsson, D ^{[1
]}

Bladh, K ^{[1
]}

Delsing, P ^{[1
]}

机构：

[1] Chalmers Univ Technol, S-41296 Gothenburg, Sweden

来源：

PHYSICAL REVIEW B | 2004年 / 69卷 / 14期

关键词：

D O I：

10.1103/PhysRevB.69.140503

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have fabricated a Josephson charge qubit by capacitively coupling a single-Cooper-pair box (SCB) to an electrometer based upon a single-electron transistor (SET) configured for radio-frequency readout (rf-SET). Charge quantization of 2e is observed and microwave spectroscopy is used to extract the Josephson and charging energies of the box. We perform coherent manipulation of the SCB by using very fast dc pulses and observe quantum oscillations in time of the charge that persist to similar or equal to10 ns. The observed contrast of the oscillations is high and agrees with that expected from the finite E-J/E-C ratio and finite rise time of the dc pulses. In addition, we are able to demonstrate nearly 100% initial charge state polarization. We also present a method to determine the relaxation time T-1 when it is shorter than the measurement time T-meas.

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页码：140503 / 1

页数：4

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