Universal nonequilibrium quantum dynamics in imaginary time
| Autor: | Anders W. Sandvik, C. De Grandi, Anatoli Polkovnikov |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Quantum phase transition
Physics Quantum Physics Quantum dynamics Quantum simulator FOS: Physical sciences Condensed Matter Physics 01 natural sciences Imaginary time 010305 fluids & plasmas Electronic Optical and Magnetic Materials Condensed Matter - Other Condensed Matter Open quantum system Quantum process Quantum mechanics 0103 physical sciences Quantum algorithm Statistical physics 010306 general physics Quantum dissipation Quantum Physics (quant-ph) Other Condensed Matter (cond-mat.other) |
| DOI: | 10.48550/arxiv.1106.4078 |
| Popis: | We propose a method to study dynamical response of a quantum system by evolving it with an imaginary-time dependent Hamiltonian. The leading non-adiabatic response of the system driven to a quantum-critical point is universal and characterized by the same exponents in real and imaginary time. For a linear quench protocol, the fidelity susceptibility and the geometric tensor naturally emerge in the response functions. Beyond linear response, we extend the finite-size scaling theory of quantum phase transitions to non-equilibrium setups. This allows, e.g., for studies of quantum phase transitions in systems of fixed finite size by monitoring expectation values as a function of the quench velocity. Non-equilibrium imaginary-time dynamics is also amenable to quantum Monte Carlo (QMC) simulations, with a scheme that we introduce here and apply to quenches of the transverse-field Ising model to quantum-critical points in one and two dimensions. The QMC method is generic and can be applied to a wide range of models and non-equilibrium setups. Comment: 8 pages, 3 figures. Expanded, final published version |
| Databáze: | OpenAIRE |
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