Precise identification of parameters governing quantum processes is a critical task for quantum information and communication technologies. In this work we consider a setting where system evolution is determined by a parameterized Hamiltonian, and the task is to estimate these parameters from temporal records of a restricted set of system observables (time traces). Based on the notion of system realization from linear systems theory we develop a constructive algorithm that provides estimates of the unknown parameters directly from these time traces. We illustrate the algorithm and its robustness to measurement noise by applying it to a one-dimensional spin chain model with variable couplings.
@article{arxiv.1401.5780,
title = {Quantum Hamiltonian identification from measurement time traces},
author = {Jun Zhang and Mohan Sarovar},
journal= {arXiv preprint arXiv:1401.5780},
year = {2014}
}
Comments
5 pages + Supplementary Information. Modified estimation algorithm to be robust to measurement noise. New results on noise robustness. Published version