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TT: Tiefe Temperaturen

TT 22: Metall-Isolator-Überg
änge in Quantensystemen II

TT 22.8: Talk

Friday, March 28, 2003, 12:00–12:15, HSZ301

Formation of three-particle clusters in hetero-junctions and MOSFET structures — •Klaus Morawetz³ and Enver Nakhmedov^1,2 — ¹TU Chemnitz, Fakultät für Elektrotechnik und Informationstechnik, D-09107 Chemnitz — ²Azerbaijan Academy of Sciences, Institute of Physics, H. Cavid 33, Baku, Azerbaijan — ³Max-Planck-Institute for the Physics of Complex Systems, Noethnitzer Str. 38, 01187 Dresden, Germany

A novel interaction mechanism in MOSFET structures and GaAs/AlGaAs hetero–junctions between the zone electrons of the two–dimensional (2D) gas and the charged traps on the insulator side is considered. By applying a canonical transformation, off–diagonal terms in the Hamiltonian due to the trapped level subsystem are excluded. This yields an effective three–particle attractive interaction as well as a pairing interaction inside the 2D electronic band. A type of Bethe- Goldstone equation for three particles is studied to clarify the character of the binding and the energy of the three-particle bound states. The results are used to offer a possible explanation of the Metal–Insulator transition recently observed in MOSFET and hetero–junctions.

[1] E. P. Nakhmedov, K. Morawetz, Phys. Rev. B 66, 195333 (2002)