Quantum memory in warm Rb vapor with buffer gas

Abstract

Quantum memory is considered to be one of the key elements in the fields of quantum computing and quantum communication. Warm atomic vapor cells for quantum memory in DLCZ (for Duan, Lukin, Cirac, and Zoller) protocol are appealing due to the perceived reduction in experimental complexity and commercial availability. However, reported results on quantum memory using warm vapor cells were done under widely different experimental conditions and produced ambiguous results. In order for the memory to exhibit non-classical behavior, to a high degree of certainty, the cross-correlation value between the Stokes and anti-Stokes photons needs to be greater than two. In this work we demonstrate quantum memory with cross-correlation value between the Stokes and anti-Stokes photons greater than two lasting for 4 μs using warm Rb vapor with buffer gas for nearly co-propagating write and read beams.