Experimental quantum-walk revival with a time-dependent coin

Phys Rev Lett. 2015 Apr 10;114(14):140502. doi: 10.1103/PhysRevLett.114.140502. Epub 2015 Apr 6.

Abstract

We demonstrate a quantum walk with time-dependent coin bias. With this technique we realize an experimental single-photon one-dimensional quantum walk with a linearly ramped time-dependent coin flip operation and thereby demonstrate two periodic revivals of the walker distribution. In our beam-displacer interferometer, the walk corresponds to movement between discretely separated transverse modes of the field serving as lattice sites, and the time-dependent coin flip is effected by implementing a different angle between the optical axis of half-wave plate and the light propagation at each step. Each of the quantum-walk steps required to realize a revival comprises two sequential orthogonal coin-flip operators, with one coin having constant bias and the other coin having a time-dependent ramped coin bias, followed by a conditional translation of the walker.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Models, Theoretical*
  • Quantum Theory*