Characterizing quantum phase transitions by single qubit operations

Details Characterizing quantum phase transitions by single qubit operations Characterizing quantum phase transitions by single qubit operations

2006-04-07

arxiv.org/abs/quant-ph/0604047v1

Physics

Quantum Physics

4 pages, 4 figures

Scientific paper

We introduce observable quantities, borrowing from concepts of quantum information theory, for the characterization of quantum phase transitions in spin systems. These observables are uniquely defined in terms of single spin unitary operations. We define the energy gap between the ground state and the state produced by the action of a single-qubit local gate. We show that this static quantity involves only single-site expectations and two-point correlation functions on the ground state. We then discuss a dynamical local observable defined as the acceleration of quantum state evolution after performing an instaneous single-qubit perturbation on the ground state. This quantity involves three-point correlations as well. We show that both the static and the dynamical observables detect and characterize completely quantum critical points in a class of spin systems.

Affiliated with

Also associated with

No associations

Rating

Characterizing quantum phase transitions by single qubit operations 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 Characterizing quantum phase transitions by single qubit operations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Characterizing quantum phase transitions by single qubit operations will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-723482