BIEXCITON kth POWER AMPLITUDE SQUEEZING DUE TO OPTICAL EXCITON BIEXCITON CONVERSION

BIEXCITON kth POWER AMPLITUDE SQUEEZING DUE TO OPTICAL EXCITON BIEXCITON CONVERSION

In the modern age each day generates nearly tens of trillion bits of information. So, among others, the demand of faster data processing with as less as possible inaccuracies has become extremely urgent. A promising solution is to exploit light in communication networks because of its many advantageous merits such as high speed, high parallelism, immunity to havocs due to lightning or/and discharges, . . . However, since all-optical information manipulation is still remote, of present real-izable applications are optoelectronic devices in which both photons and electrons (excitons, polarons, plasmons, . . .) play their own roles. Most current optoelectronic

devices use laser light which is coherent and thus the precision level is bound to the standard quantum limit (SQL). The clear strategy to beat the SQL is to utilize squeezed beams of light1,2 because in a squeezed state (see, e.g. Refs. 3 and 4) noise in an observable can be reduced below the SQL (of course, at the expense of in-creased noise in the other “noncommutative”observable). The concept of squeezed states apply also to electronic quasiparticles in matter. Therefore, a challenge in fu-ture optoelectronic devices would be the self-consistent description of light-matter interaction when both light and matter quasiparticles are squeezed. Meanwhile, mechanisms are sought for squeezing photons (see, e.g. Refs. 5 to 10) as well as matter quasiparticles like excitons,11,12 biexcitons,13,14 polarons,15 phonons,16-18 trapped atoms,19,20 spinons,21 etc.

Concerning squeezed biexcitons a semiclassical model was suggested in Ref. 13.

Recently, biexciton squeezing has been considered using a fully quantum trilinear

Hamiltonian14. In the present paper, we extend the result of Ref. 14 to the so called

kth power amplitude squeezing (KPAS). This is motivated by the fact that with

the advanced techniques in higher-order correlation measurements signals could be

impressed on and extracted from the kth power of the field amplitude components.

Then, squeezing the variable corresponding to a kth power amplitude component proves to be meaningful. In fact, squeezing of the square of the field amplitude (i.e.,

for k = 2) was proposed for the first time in Ref. 22. Soon afterwards, a good deal of papers have been devoted to the possibility of KPAS for any k in various physical

schemes23-31 . To avoid ambiguity we shall speak of KPAS when k > 1, while the case of k = 1 is referred to as normal squeezing (NS)..

see here for details