# Experimentally realizable states for bosonic quantum fields

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I would like to know which type of quantum states of a bosonic field, that have an explicit analytical expression as vectors/density matrices in a symmetric Fock space, can be prepared in an experimental setting, and then manipulated (e.g. an interaction can be turned on and they are evolved by the resulting dynamics).

I think that coherent states can be prepared via lasers (even if I know there is some debate on that), and I have been told (do you know any reference?) that states with a fixed number $n$ of photons (Fock sates) have also been recently realized. But what about more general, or simply different, states (e.g. twin Fock states, statistical mixtures, eigenvectors of operators (with discrete spectrum)...)?

I am interested in established results, and precise references would be greatly appreciated.

This post imported from StackExchange Physics at 2015-05-13 18:52 (UTC), posted by SE-user yuggib

asked Apr 27, 2015
edited May 14, 2015
This is an awfully broad question, you might like to refine your requirements a bit. For example, thermal states of bosonic fields (black-body radiation field, acoustic phonons in crystals) are ubiquitous. Fock states of photons were first unambiguously detected in the 1970s and are now routinely prepared by single-photon sources. Quantum state preparation of electromagnetic field cavity modes won Serge Haroche the Nobel Prize, etc...

This post imported from StackExchange Physics at 2015-05-13 18:52 (UTC), posted by SE-user Mark Mitchison
@MarkMitchison I narrowed it a bit. I am interested in states that have an explicit analytical form and can be prepared as "initial states" of an experiment and not just only observed. Thanks for the references anyways ;-)

This post imported from StackExchange Physics at 2015-05-13 18:52 (UTC), posted by SE-user yuggib

## 1 Answer

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Discrete states are routinely prepared in quantum information theory. This means that one cares only about two levels per degree of freedom, and uses quantum gates to manipulate these.

Since you ask for states with analytical form there is not much more. Squeezed states of light can be created and have an explicit analytic form, and finite superpositions of these can be prepared, too. There is a useful article Squeezed states of light by Fabre on this; a random recent paper is http://arxiv.org/abs/1504.03904

answered May 14, 2015 by (12,355 points)

Thanks for the refs ;-)

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