Repulsive polarons in two-dimensional Fermi gases

Bibliographic Details
Title: Repulsive polarons in two-dimensional Fermi gases
Authors: Ngampruetikorn, V., Levinsen, J., Parish, Meera M.
Source: Europhys. Lett. 98, 30005 (2012)
Publication Year: 2011
Collection: Condensed Matter
Subject Terms: Condensed Matter - Quantum Gases
More Details: We consider a single spin-down impurity atom interacting via an attractive, short-range potential with a spin-up Fermi sea in two dimensions (2D). Similarly to 3D, we show how the impurity can form a metastable state (the "repulsive polaron") with energy greater than that of the non-interacting impurity. Moreover, we find that the repulsive polaron can acquire a finite momentum for sufficiently weak attractive interactions. Even though the energy of the repulsive polaron can become sizeable, we argue that saturated ferromagnetism is unfavorable in 2D because of the polaron's finite lifetime and small quasiparticle weight.
Comment: 6 pages, 3 figures
Document Type: Working Paper
DOI: 10.1209/0295-5075/98/30005
Access URL: http://arxiv.org/abs/1110.6415
Accession Number: edsarx.1110.6415
Database: arXiv
More Details
DOI:10.1209/0295-5075/98/30005