Projects per year
Abstract
We develop a notion of stochastic quantum trajectories. First, we construct a basis set of trajectories, called elementary trajectories, and go on to show that any quantum dynamical process, including those that are nonMarkovian, can be expressed as a linear combination of this set. We then show that the set of processes divide into two natural classes: those that can be expressed as a convex mixture of elementary trajectories and those that cannot be. The former are shown to be entanglement breaking processes (in each step), while the latter are dubbed coherent processes. This division of processes is analogous to separable and entangled states. In the second half of the paper, we show, with an information theoretic game, that when a process is nonMarkovian, coherent trajectories allow for decoupling from the environment while preserving arbitrary quantum information encoded into the system. We give explicit expressions for the temporal correlations (quantifying nonMarkovianity) and show that, in general, there are more quantum correlations than classical ones. This shows that nonMarkovian quantum processes are indeed fundamentally different from their classical counterparts. Furthermore, we demonstrate how coherent trajectories (with the aid of coherent control) could turn nonMarkovianity into a resource. In the final section of the paper we explore this phenomenon in a geometric picture with a convenient set of basis trajectories.
Original language  English 

Article number  414014 
Number of pages  22 
Journal  Journal of Physics A: Mathematical and Theoretical 
Volume  51 
Issue number  41 
DOIs  
Publication status  Published  14 Sept 2018 
Keywords
 coherent dynamics
 nonMarkovian
 stochastic trajectory
Projects
 1 Finished

Characterising complex quantum dynamics for technological applications
Australian Research Council (ARC), Monash University
1/01/17 → 31/12/20
Project: Research