Projects per year
Abstract
Memoryless processes are ubiquitous in nature, in contrast with the mathematics of open systems theory, which states that nonMarkovian processes should be the norm. This discrepancy is usually addressed by subjectively making the environment forgetful. Here we prove that there are physical nonMarkovian processes that with high probability look highly Markovian for all orders of correlations; we call this phenomenon Markovianization. Formally, we show that when a quantum process has dynamics given by an approximate unitary design, a large deviation bound on the size of nonMarkovian memory is implied. We exemplify our result employing an efficient construction of an approximate unitary circuit design using twoqubit interactions only, showing how seemingly simple systems can speedily become forgetful. Conversely, since the process is closed, it should be possible to detect the underlying nonMarkovian effects. However, for these processes, observing nonMarkovian signatures would require highly entangling resources and hence be a difficult task.
Original language  English 

Article number  127 
Number of pages  11 
Journal  Communications Physics 
Volume  4 
Issue number  1 
DOIs  
Publication status  Published  Dec 2021 

Outmaneuvering correlated noise in quantum computers
Modi, K. & Hill, C.
26/04/22 → 26/04/25
Project: Research

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