Scattering Rates and Lifetime of Exact and Boson Excitons

Combescot, Monique; Betbeder‐Matibet, O.

doi:10.1103/physrevlett.93.016403

Cited by 41 publications

(63 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To possibly treat their interactions through available many-body procedures -valid for elementary quantum particles only [12,13], -excitons are commonly considered as elementary bosons, their composite nature being hidden through the Coulomb exchange term of the exciton-exciton scattering in the exciton effective Hamiltonian generated by the "bosonization" procedure. In previous works, we have shown that not only the effective exciton-exciton scattering up to now used [14] should have been rejected long ago because it induces an unphysical non hermiticity in the effective exciton Hamiltonian [15], but, worse, there is no way to properly treat the interactions between excitons through an effective potential between elementary bosons, whatever the exciton-exciton scatterings are [9,16]. All our works on exciton many-body effects end with the same conclusion : It is not possible to forget the composite nature of the excitons by reducing them to elementary bosons, whatever the bosonization procedure is.…”

Section: Pacsmentioning

confidence: 99%

See 1 more Smart Citation

Polariton-polariton scattering: Exact results through a novel approach

2007

View full text Add to dashboard Cite

We present a fully microscopic approach to the transition rate of two excitonphoton polaritons. The non-trivial consequences of the polariton composite nature -here treated exactly through a development of our composite-exciton manybody theory -lead to results noticeably different from the ones of the conventional approaches in which polaritons are mapped into elementary bosons. Our work reveals an appealing fundamental scattering which corresponds to a photon-assisted exchange -in the absence of Coulomb process. This scattering being dominant when one of the scattered polaritons has a strong photon character, it should be directly accessible to experiment. In the case of microcavity polaritons, it produces a significant enhancement of the polariton transition rate when compared to the one coming from Coulomb interaction. This paper also contains the crucial tools to securely tackle the many-body physics of polaritons, in particular towards its possible BEC.

show abstract

Section: Pacsmentioning

confidence: 99%

“…To get the polariton transition rate, we barely follow the procedure we have already used to get the exciton transition rate [9,16]. When H does not split as H 0 + V , the standard form of the Fermi golden rule cannot be used.…”

Section: Polariton Transition Ratementioning

confidence: 99%

Polariton-polariton scattering: Exact results through a novel approach

2007

View full text Add to dashboard Cite

show abstract

“…The transition rate towards another electron-trion state (K e , J ) must be identified with [15,16] t…”

Section: Methodsmentioning

confidence: 99%

Effect of fermionic components on trion–electron scattering

Combescot¹,

Betbeder‐Matibet²,

Dupertuis³

2008

Solid State Communications

Self Cite

View full text Add to dashboard Cite

a b s t r a c tTo test the validity of replacing a composite fermion by an elementary fermion, we calculate the transition rate from a state made of one free electron and one trion to a similar electron-trion pair, through the time evolution of such a pair induced by Coulomb interaction between elementary fermions. It is convenient to describe trion as one electron interacting with one exciton. This allows us to use the tools we have developed in the new composite-exciton many-body theory. The trion-electron scattering contains a direct channel in which ''in'' and ''out'' trions are made with the same fermions, and an exchange channel in which the ''in'' free electron becomes one of the ''out'' trion components. As expected, momenta are conserved in these two channels. The direct scattering is found to read as the bare Coulomb potential between elementary particles multiplied by a form factor which depends on the ''in'' and ''out'' trion relative motion indices η and η , this factor reducing to δ ηη in the zero momentum transfer limit. In this direct channel, the trion at large distance reacts as an elementary particle, its composite nature showing up at large momentum transfer. In contrast, the fact that the trion is not elementary does affect the exchange channel for all momentum transfers. We thus conclude that a 3-component fermion behaves as an elementary fermion for direct processes in the small momentum transfer limit only.

show abstract

“…It turns out that, as briefly rederived below, ξ out in which Coulomb interaction takes place after carrier exchange, does not enter the effective scattering ruling the time evolution of two excitons 35,36 . This is due to a very fundamental reason linked to symmetry breaking in the evolution towards positive time.…”

Section: Introductionmentioning

confidence: 99%

Fundamental collapse of the exciton-exciton effective scattering

et al. 2010

View full text Add to dashboard Cite

The exciton-exciton effective scattering which rules the time evolution of two excitons is studied as a function of initial momentum difference, scattering angle and electron-to-hole mass ratio. We show that this effective scattering can collapse for energy-conserving configurations provided that the difference between the two initial exciton momenta is larger than a threshold value. Sizeable scatterings then exist in the forward direction only. We even find that, for an electron-to-hole mass ratio close to 1/2, the exciton-exciton effective scattering stays close to zero in all directions when the difference between the initial exciton momenta has a very specific value. This unexpected but quite remarkable collapse comes from tricky compensation between direct and exchange Coulomb processes which originates from the fundamental undistinguishability of the exciton fermionic components.

show abstract

Scattering Rates and Lifetime of Exact and Boson Excitons

Cited by 41 publications

References 18 publications

Polariton-polariton scattering: Exact results through a novel approach

Polariton-polariton scattering: Exact results through a novel approach

Effect of fermionic components on trion–electron scattering

Fundamental collapse of the exciton-exciton effective scattering

Contact Info

Product

Resources

About