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Detecting Topological Invariants in Nonunitary Discrete-Time Quantum Walks.

Author
Abstract
:

We report the experimental detection of bulk topological invariants in nonunitary discrete-time quantum walks with single photons. The nonunitarity of the quantum dynamics is enforced by periodically performing partial measurements on the polarization of the walker photon, which effectively introduces loss to the dynamics. The topological invariant of the nonunitary quantum walk is manifested in the quantized average displacement of the walker, which is probed by monitoring the photon loss. We confirm the topological properties of the system by observing localized edge states at the boundary of regions with different topological invariants. We further demonstrate the robustness of both the topological properties and the measurement scheme of the topological invariants against disorder.

Year of Publication
:
2017
Journal
:
Physical review letters
Volume
:
119
Issue
:
13
Number of Pages
:
130501
Date Published
:
2017
ISSN Number
:
0031-9007
URL
:
http://link.aps.org/abstract/PRL/v119/p130501
DOI
:
10.1103/PhysRevLett.119.130501
Short Title
:
Phys Rev Lett
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