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TT: Tiefe Temperaturen
TT 18: Superconductivity: Borides, Borocarbides, Carbides, ...
TT 18.12: Talk
Tuesday, March 28, 2006, 18:00–18:15, HSZ 02
Cooper pairing on a sphere: multielectron bubbles in helium — •Jacques Tempere1,2, Vladimir Gladilin1, Jozef Devreese1, and Isaac Silvera2 — 1TFVS, Universiteit Antwerpen, Universiteitsplein 1, 2610 Antwerpen, Belgium — 2Lyman Laboratory of Physics, Harvard University, Cambridge MA, USA
Electrons on helium constitute a versatile realization of a two-dimensional electron gas. Multielectron bubbles are cavities inside liquid helium, containing electrons that collect at the surface of the bubble, forming a spherical two-dimensional electron gas. In this contribution, we investigate the effects of the electron-ripplon interaction on the spherical electron system. We derive the conditions for which the electron-ripplon interaction can lead to an attractive interaction between the electrons, and to pairing. The paired state is described using Richardson’s method. The density of states, the pair-breaking gap, and the ground state level occupations are derived and discussed. The difference between Cooper pairing in a flat electron system and Cooper pairing on a sphere are highlighted. Finally, progress in the experimental realization of this system is discussed.