Observations Outside the Light-Cone: Algorithms for Non-Equilibrium and Thermal States

Details Observations Outside the Light-Cone: Algorithms for Non-Equilibrium and Thermal States Observations Outside the Light-Cone: Algorithms for Non-Equilibrium and Thermal States

2008-01-14

arxiv.org/abs/0801.2161v1

Phys. Rev. B 77, 144302 (2008).

Physics

Quantum Physics

19 pages, 12 figures

Scientific paper

10.1103/PhysRevB.77.144302

We apply algorithms based on Lieb-Robinson bounds to simulate time-dependent and thermal quantities in quantum systems. For time-dependent systems, we modify a previous mapping to quantum circuits to significantly reduce the computer resources required. This modification is based on a principle of "observing" the system outside the light-cone. We apply this method to study spin relaxation in systems started out of equilibrium with initial conditions that give rise to very rapid entanglement growth. We also show that it is possible to approximate time evolution under a local Hamiltonian by a quantum circuit whose light-cone naturally matches the Lieb-Robinson velocity. Asymptotically, these modified methods allow a doubling of the system size that one can obtain compared to direct simulation. We then consider a different problem of thermal properties of disordered spin chains and use quantum belief propagation to average over different configurations. We test this algorithm on one dimensional systems with mixed ferromagnetic and anti-ferromagnetic bonds, where we can compare to quantum Monte Carlo, and then we apply it to the study of disordered, frustrated spin systems.

Affiliated with

Also associated with

No associations

Rating

Observations Outside the Light-Cone: Algorithms for Non-Equilibrium and Thermal States 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 Observations Outside the Light-Cone: Algorithms for Non-Equilibrium and Thermal States, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Observations Outside the Light-Cone: Algorithms for Non-Equilibrium and Thermal States will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-150234