Improving Quantum State Estimation with Mutually Unbiased Bases

TL;DR

This paper experimentally demonstrates that using mutually unbiased bases in quantum state tomography significantly improves the accuracy of two-qubit polarization state estimation compared to standard methods.

Contribution

First experimental implementation of quantum state tomography utilizing mutually unbiased bases for two-qubit states, showing enhanced estimation accuracy.

Findings

Infidelity reduced by up to 1.84 times with the new method

Method outperforms standard state estimation strategies

Experimental validation across three different quantum states

Abstract

When used in quantum state estimation, projections onto mutually unbiased bases have the ability to maximize information extraction per measurement and to minimize redundancy. We present the first experimental demonstration of quantum state tomography of two-qubit polarization states to take advantage of mutually unbiased bases. We demonstrate improved state estimation as compared to standard measurement strategies and discuss how this can be understood from the structure of the measurements we use. We experimentally compared our method to the standard state estimation method for three different states and observe that the infidelity was up to 1.84+/-0.06 times lower using our technique than it was using standard state estimation methods.