Entanglement under noisy environments: From quantum computation to quantum many-body physics
ABSTRACT :
Entanglement has been proved to be an indispensable resource in quantum information processing tasks. However, a major problem in using entangled states in quantum protocols is its fragility under noisy environments. We discuss the characteristics of entanglement under different kinds of noise in measurement based quantum computing (MBQC) and in quantum many-body physics. We demonstrate how entanglement behaves against system size and noise strength when the resource states of MBQC is subjected to noise. We also consider quantum spin systems under noise, and show that entanglement can remain frozen over a finite time-interval when subjected to local noise. We draw a connection between the freezing of entanglement and the propagation of information through the spin chain. We also discuss the behaviour of entanglement in the quantum spin chain if when the initial state is factorized, and point out a complementary behaviour with freezing of entanglement.