Incoherent Qubit Control Using the Quantum Zeno Effect

The quantum Zeno effect is the suppression of Hamiltonian evolution by repeated observation, which pins the system to an eigenstate of the measurement observable. Using measurement alone, control of the state can be achieved if the observable is slowly varied, so that the state tracks the now time-d...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2018-01, Vol.120 (2), p.020505-020505, Article 020505
Main Authors: Hacohen-Gourgy, S, García-Pintos, L P, Martin, L S, Dressel, J, Siddiqi, I
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The quantum Zeno effect is the suppression of Hamiltonian evolution by repeated observation, which pins the system to an eigenstate of the measurement observable. Using measurement alone, control of the state can be achieved if the observable is slowly varied, so that the state tracks the now time-dependent eigenstate. We demonstrate this using a circuit-QED readout technique that couples to a dynamically controllable observable of a qubit. Continuous monitoring of the measurement record allows us to detect an escape from the eigenstate, thus serving as a built-in form of error detection. We show this by postselecting on realizations with high fidelity with respect to the target state. Our dynamical measurement operator technique offers a new tool for numerous forms of quantum feedback protocols, including adaptive measurements and rapid state purification.
ISSN:0031-9007
1079-7114
DOI:10.1103/PhysRevLett.120.020505