Physics – Quantum Physics
Scientific paper
2007-07-26
Physics
Quantum Physics
7 pages, 6 figures, revised and extended
Scientific paper
10.1103/PhysRevA.78.022313
We present a general and exact formalism for finding the evolution of a quantum system subject to external telegraph noise. The various qubit decoherence rates are determined by the eigenvalues of a transfer matrix. The formalism can be applied to a qubit subject to an arbitrary combination of dephasing and relaxational telegraph noise, in contrast to existing non-perturbative methods that treat only one or the other of these limits. We present 3 applications: 1) We obtain the full qubit dynamics on time scales short compared with the enviromental correlation times. In the strong coupling cases this reveals unexpected oscillations and induced magnetization components; 2) We find in strong coupling case strong violations of the widely used relation 1/T$_2$ = 1/2T$_1$ + 1/T$_{\phi}$, which is a result of perturbation theory; 3) We discuss the effects of bang-bang and spin-echo controls of the qubit dynamics in general settings of the telegraph noises. %The result shows that these methods are not very effective in %reducing decoherence arising from a single telegraph noise. Finally, we discuss the extension of the method to the cases of many telegraph noise sources and multiple qubits. The method still works when white noise is also present.
Cheng Bin
Joynt Robert
Wang Qiang-Hua
No associations
LandOfFree
Exact solution of a model of qubit dephasing due to telegraph noise does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Exact solution of a model of qubit dephasing due to telegraph noise, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Exact solution of a model of qubit dephasing due to telegraph noise will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-40445