Repulsive Fermi polarons in a resonant mixture of ultracold 6Li atoms
We employ radio-frequency spectroscopy to investigate a polarized spin mixture of ultracold 6 Li atoms close to a broad Feshbach scattering resonance. Focusing on the regime of strong repulsive interactions, we observe well-defined coherent quasiparticles even for unitarity-limited interactions. We...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/116043 |
| Acceso en línea: | https://hdl.handle.net/2117/116043 https://dx.doi.org/10.1103/PhysRevLett.118.083602 |
| Access Level: | acceso abierto |
| Palabra clave: | Thermodynamics Quantum theory Fermi gases polarons Physical Systems Ultracold gases resonance Spectroscopy Condensed Matter & Materials PhysicsAtomic Molecular & Optical Termodinàmica Quàntums, Teoria dels Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Telecomunicació òptica::Fotònica |
| Sumario: | We employ radio-frequency spectroscopy to investigate a polarized spin mixture of ultracold 6 Li atoms close to a broad Feshbach scattering resonance. Focusing on the regime of strong repulsive interactions, we observe well-defined coherent quasiparticles even for unitarity-limited interactions. We characterize the many-body system by extracting the key properties of repulsive Fermi polarons: the energy E + , the effective mass m * , the residue Z , and the decay rate G . Above a critical interaction, E + is found to exceed the Fermi energy of the bath, while m * diverges and even turns negative, thereby indicating that the repulsive Fermi liquid state becomes energetically and thermodynamically unstable. |
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