Bound states in two-dimensional Fermi systems with quadratic band touching
| Autor: | Rodrigo G. Pereira, M. C. O. Aguiar, Flávio L. N. Santos, M. A. Caracanhas |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Physics
Condensed Matter::Quantum Gases Strongly Correlated Electrons (cond-mat.str-el) Binding energy Exchange interaction FOS: Physical sciences Propagator 02 engineering and technology Renormalization group 021001 nanoscience & nanotechnology 01 natural sciences Momentum Condensed Matter - Strongly Correlated Electrons MAGNETISMO Quantum Gases (cond-mat.quant-gas) Quantum mechanics 0103 physical sciences Bound state Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Degeneracy (mathematics) Anisotropy Condensed Matter - Quantum Gases |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | The formation of bound states between mobile impurity particles and fermionic atoms has been demonstrated in spin-polarized Fermi gases with attractive interspecies interaction. We investigate bound states of mobile impurities immersed in a two-dimensional system with a symmetry-protected quadratic band touching. In addition to the standard s-wave interaction, we consider an anisotropic dipolar exchange interaction that locally breaks point group symmetries. Using a weak-coupling renormalization group approach and a ladder approximation for the impurity-fermion propagator, we establish that the number of bound states can be controlled by varying the anisotropy of the exchange interaction. Our results show that the degeneracy and momentum dependence of the binding energies reflect some distinctive properties of the quadratic band touching. 9 pages, 8 figures |
| Databáze: | OpenAIRE |
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