Nondemolition measurement of the vacuum state or its complement

Oi, Daniel K. L. and Potocek, Vaclav and Jeffers, John (2013) Nondemolition measurement of the vacuum state or its complement. Physical Review Letters, 110 (21). 210504. ISSN 1079-7114 (

[thumbnail of OietalPRL2013-nondemolition-measurement-of-the-vacuum]
PDF. Filename: OietalPRL2013_nondemolition_measurement_of_the_vacuum.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo

Download (1MB)| Preview


Measurement is integral to quantum information processing and communication; it is how information encoded in the state of a system is transformed into classical signals for further use. In quantum optics, measurements are typically destructive, so that the state is not available afterwards for further steps. Here we show how to measure the presence or absence of the vacuum in a quantum optical field without destroying the state, implementing the ideal projections onto the respective subspaces. This not only enables sequential measurements, useful for quantum communication, but it can also be adapted to create novel states of light via bare raising and lowering operators.