1108.5138 (Alberto Montina)

Dynamics of a qubit as a classical stochastic process with
time-correlated noise: minimal measurement invasiveness    [PDF]

Alberto Montina

So far it has been shown that the quantum dynamics cannot be described as a
classical Markov process unless the number of classical states is uncountably
infinite. In this paper, we present a stochastic model with time-correlated
noise that exactly reproduces any unitary evolution of a qubit and requires
just four classical states. The invasive updating of just one bit during a
measurement accounts for the quantum violation of the Leggett-Garg
inequalities. Unlike in a pilot wave theory, the stochastic forces governing
the jumps among the four states do not depend on the quantum state, but only on
the unitary evolution. This model is used to derive a local hidden variable
model, augmented by one bit of classical communication, for simulating
entangled Bell states.

View original: http://arxiv.org/abs/1108.5138