Optimal suppression of defect generation during a passage across a quantum critical point

Ning Wu, Arun Nanduri, Herschel Rabitz

Research output: Contribution to journalArticlepeer-review

11 Scopus citations

Abstract

The dynamics of quantum phase transitions are inevitably accompanied by the formation of defects when crossing a quantum critical point. For a generic class of quantum critical systems, we solve the problem of minimizing the production of defects through the use of a gradient-based deterministic optimal control algorithm. By considering a finite-size quantum Ising model with a tunable global transverse field, we show that an optimal power-law quench of the transverse field across the Ising critical point works well at minimizing the number of defects, in spite of being drawn from a subset of quench profiles. These power-law quenches are shown to be inherently robust against noise. The optimized defect density exhibits a transition at a critical ratio of the quench duration to the system size, which we argue coincides with the intrinsic speed limit for quantum evolution.

Original languageEnglish (US)
Article number041115
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume91
Issue number4
DOIs
StatePublished - Jan 26 2015

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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