TY - JOUR

T1 - A continuous-time diffusion limit theorem for dynamical decoupling and intrinsic decoherence

AU - Hillier, Robin

AU - Arenz, Christian

AU - Burgarth, Daniel

N1 - Hillier, R., Arenz, C., Burgarth, D. (2015). A continuous-time diffusion limit theorem for dynamical decoupling and intrinsic decoherence. Journal of Physics A: Mathematical and Theoretical, 48 (15), [155301].

PY - 2015/3/25

Y1 - 2015/3/25

N2 - We discuss a few mathematical aspects of random dynamical decoupling, a key tool procedure in quantum information theory. In particular, we place it in the context of discrete stochastic processes, limit theorems and completely positive trace-preserving semigroups on matrix algebras. We obtain precise analytical expressions for expectation and variance of the density matrix and fidelity over time in the continuum-time limit depending on the system Lindbladian, which then lead to rough short-time estimates depending only on certain coupling strengths. We prove that dynamical decoupling does not work in the case of intrinsic (i.e., not environment-induced) decoherence, and together with the above-mentioned estimates this yields a novel method of partially identifying intrinsic decoherence.

AB - We discuss a few mathematical aspects of random dynamical decoupling, a key tool procedure in quantum information theory. In particular, we place it in the context of discrete stochastic processes, limit theorems and completely positive trace-preserving semigroups on matrix algebras. We obtain precise analytical expressions for expectation and variance of the density matrix and fidelity over time in the continuum-time limit depending on the system Lindbladian, which then lead to rough short-time estimates depending only on certain coupling strengths. We prove that dynamical decoupling does not work in the case of intrinsic (i.e., not environment-induced) decoherence, and together with the above-mentioned estimates this yields a novel method of partially identifying intrinsic decoherence.

KW - central limit theorem

KW - CPT semigroups

KW - dynamical decoupling

KW - intrinsic decoherence

UR - http://www.scopus.com/inward/record.url?scp=84925830595&partnerID=8YFLogxK

UR - http://hdl.handle.net/2160/28665

U2 - 10.1088/1751-8113/48/15/155301

DO - 10.1088/1751-8113/48/15/155301

M3 - Article

AN - SCOPUS:84925830595

SN - 1751-8113

VL - 48

SP - 1

EP - 27

JO - Journal of Physics A: Mathematical and Theoretical

JF - Journal of Physics A: Mathematical and Theoretical

IS - 15

M1 - 155301

ER -