Measuring the polarisation of a single photon without destroying it

Gilles Nogues, Arno Rauschenbeutel, S. Osnaghi +3 more

Manpreet Kaur, Mandip Singh

A transparent polarisation sensitive phase pattern makes a polarisation dependent transformation of quantum state of photons without absorbing them. Such an invisible pattern can be imaged with quantum entangled photons by making joint quantum measurements on photons. This paper shows a long path experiment to quantum image a transparent polarisation sensitive phase pattern with hyper-entangled photon pairs involving momentum and polarisation degrees of freedom. In the imaging configuration, a single photon interacts with the pattern while the other photon, which has never interacted with the pattern, is measured jointly in a chosen polarisation basis and in a quantum superposition basis of its position which is equivalent to measure its momentum. Individual photons of each hyper-entangled pair cannot provide a complete image information. The image is constructed by measuring the polarisation state and position of the interacting photon corresponding to a measurement outcome of the non-interacting photon. This paper presents a detailed concept, theory and free space long path experiments on quantum imaging of polarisation sensitive phase patterns.

Jeremy L. O’Brien, Geoff J. Pryde, AG White +2 more

Cody McKenzie, Preston Alexander, R. Seth Smith

Jan Ole Ernst, Juan-Rafael Álvarez, Thomas D. Barrett +1 more

Abstract Photonic qubits play an instrumental role in the development of advanced quantum technologies, including quantum networking, boson sampling and measurement based quantum computing. A promising framework for the deterministic production of indistinguishable single photons is an atomic emitter coupled to a single mode of a high finesse optical cavity. Polarisation control is an important cornerstone, particularly when the polarisation defines the state of a quantum bit. Here, we propose a scheme for producing bursts of polarised single photons by coupling a generalised atomic emitter to an optical cavity, exploiting a particular choice of quantisation axis. In connection with two re-preparation methods, simulations predict ten-photon bursts coincidence count rates on the order of 1 kHz with single 87 R b atoms trapped in a state of the art optical cavity. This paves the way for novel n-photon experiments with atom-cavity sources.

Yu.P. Peresun'ko, Valentin F. Boldyshev, E.A. Vinokurov