Continuous weak measurement of the macroscopic quantum coherent oscillations of magnetic flux
نویسندگان
چکیده
منابع مشابه
Continuous weak measurement of quantum coherent oscillations
We consider the problem of continuous quantum measurement of coherent oscillations between two quantum states of an individual two-state system. It is shown that the interplay between the information acquisition and the backaction dephasing of the oscillations by the detector imposes a fundamental limit, equal to four, on the signal-to-noise ratio of the measurement. The limit is universal, e.g...
متن کاملComment on ‘‘Continuous Quantum Measurement: Inelastic Tunneling and Lack of Current Oscillations’’ A recent Letter [1] revisits the problem of continuous weak measurement of quantum coherent oscillations of a qubit
A recent Letter [1] revisits the problem of continuous weak measurement of quantum coherent oscillations of a qubit with a linear detector, the role of which is played by the quantum point contact (QPC) in the low-transparency regime. Previous studies of this problem [2–5] demonstrated that the qubit oscillations with the frequency should be reflected in the spectral density S ! of the detector...
متن کاملMacroscopic resonant tunneling of magnetic flux
We have developed a quantitative theory of resonant tunneling of magnetic flux between discrete macroscopically distinct quantum states in superconducting quantum interference device systems. The theory is based on the standard density-matrix approach. Its elements include the discussion of the two different relaxation mechanisms that exist for the double-well potential, and description of the ...
متن کاملQuantum Zeno stabilization in weak continuous measurement of two qubits
We have studied quantum coherent oscillations of two qubits under continuous measurement by a symmetrically coupled mesoscopic detector. The analysis is based on a Bayesian formalism that is applicable to individual quantum systems. Measurement continuously collapses the two-qubit system to one of the subspaces of the Bell basis. For a detector with linear response this corresponds to measureme...
متن کاملCoherent temporal oscillations of macroscopic quantum states in a Josephson junction.
We report the generation and observation of coherent temporal oscillations between the macroscopic quantum states of a Josephson tunnel junction by applying microwaves with frequencies close to the level separation. Coherent temporal oscillations of excited state populations were observed by monitoring the junction's tunneling probability as a function of time. From the data, the lower limit of...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physica C: Superconductivity
سال: 2001
ISSN: 0921-4534
DOI: 10.1016/s0921-4534(00)01705-6