Physics – Quantum Physics
Scientific paper
2001-04-18
Phys. Rev. E 64, 056226 (2001)
Physics
Quantum Physics
15 pages, 15 figures
Scientific paper
10.1103/PhysRevE.64.056226
We study the properties of spectra and eigenfunctions for a chain of $1/2- $spins (qubits) in an external time-dependent magnetic field, and under the conditions of non-selective excitation (when the amplitude of the magnetic field is large). This model is known as a possible candidate for experimental realization of quantum computation. We present the theory for finding delocalization transition and show that for the interaction between nearest qubits, the transition is very different from that to quantum chaos. We explain this phenomena by showing that in the considered region of parameters our model is close to an integrable one. According to a general opinion, the threshold for the onset of quantum chaos due to the interqubit interaction decreases with an increase of the number of qubits. Contrary to this expectation, for a magnetic field with constant gradient we have found that chaos border does not depend on the number of qubits. We give analytical estimates which explain this effect, together with numerical data supporting our analysis. Random models with long-range interactions are studied as well. In particular, we show that in this case the delocalization and quantum chaos borders coincide.
Berman Gennady P.
Borgonovi Fausto
Izrailev Felix M.
Tsifrinovich Vladimir I.
No associations
LandOfFree
Delocalization border and onset of chaos in a model of quantum computation 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 Delocalization border and onset of chaos in a model of quantum computation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Delocalization border and onset of chaos in a model of quantum computation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-564615