Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium
The notion of a polaron, originally introduced in the context of electrons in ionic lattices, helps us to understand how a quantum impurity behaves when being immersed in and interacting with a many-body background. We discuss the impact of the impurities on the medium particles by considering feedb...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-03-01
|
| Series: | Atoms |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2218-2004/9/1/18 |
| _version_ | 1797542100396408832 |
|---|---|
| author | Hiroyuki Tajima Junichi Takahashi Simeon I. Mistakidis Eiji Nakano Kei Iida |
| author_facet | Hiroyuki Tajima Junichi Takahashi Simeon I. Mistakidis Eiji Nakano Kei Iida |
| author_sort | Hiroyuki Tajima |
| collection | DOAJ |
| description | The notion of a polaron, originally introduced in the context of electrons in ionic lattices, helps us to understand how a quantum impurity behaves when being immersed in and interacting with a many-body background. We discuss the impact of the impurities on the medium particles by considering feedback effects from polarons that can be realized in ultracold quantum gas experiments. In particular, we exemplify the modifications of the medium in the presence of either Fermi or Bose polarons. Regarding Fermi polarons we present a corresponding many-body diagrammatic approach operating at finite temperatures and discuss how mediated two- and three-body interactions are implemented within this framework. Utilizing this approach, we analyze the behavior of the spectral function of Fermi polarons at finite temperature by varying impurity-medium interactions as well as spatial dimensions from three to one. Interestingly, we reveal that the spectral function of the medium atoms could be a useful quantity for analyzing the transition/crossover from attractive polarons to molecules in three-dimensions. As for the Bose polaron, we showcase the depletion of the background Bose-Einstein condensate in the vicinity of the impurity atom. Such spatial modulations would be important for future investigations regarding the quantification of interpolaron correlations in Bose polaron problems. |
| first_indexed | 2024-03-10T13:24:53Z |
| format | Article |
| id | doaj.art-2a00018261514207acabb9cd1612b72d |
| institution | Directory Open Access Journal |
| issn | 2218-2004 |
| language | English |
| last_indexed | 2024-03-10T13:24:53Z |
| publishDate | 2021-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atoms |
| spelling | doaj.art-2a00018261514207acabb9cd1612b72d2023-11-21T09:40:49ZengMDPI AGAtoms2218-20042021-03-01911810.3390/atoms9010018Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose MediumHiroyuki Tajima0Junichi Takahashi1Simeon I. Mistakidis2Eiji Nakano3Kei Iida4Department of Mathematics and Physics, Kochi University, Kochi 780-8520, JapanDepartment of Electronic and Physical Systems, Waseda University, Tokyo 169-8555, JapanCenter for Optical Quantum Technologies, Department of Physics, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, GermanyDepartment of Mathematics and Physics, Kochi University, Kochi 780-8520, JapanDepartment of Mathematics and Physics, Kochi University, Kochi 780-8520, JapanThe notion of a polaron, originally introduced in the context of electrons in ionic lattices, helps us to understand how a quantum impurity behaves when being immersed in and interacting with a many-body background. We discuss the impact of the impurities on the medium particles by considering feedback effects from polarons that can be realized in ultracold quantum gas experiments. In particular, we exemplify the modifications of the medium in the presence of either Fermi or Bose polarons. Regarding Fermi polarons we present a corresponding many-body diagrammatic approach operating at finite temperatures and discuss how mediated two- and three-body interactions are implemented within this framework. Utilizing this approach, we analyze the behavior of the spectral function of Fermi polarons at finite temperature by varying impurity-medium interactions as well as spatial dimensions from three to one. Interestingly, we reveal that the spectral function of the medium atoms could be a useful quantity for analyzing the transition/crossover from attractive polarons to molecules in three-dimensions. As for the Bose polaron, we showcase the depletion of the background Bose-Einstein condensate in the vicinity of the impurity atom. Such spatial modulations would be important for future investigations regarding the quantification of interpolaron correlations in Bose polaron problems.https://www.mdpi.com/2218-2004/9/1/18polaronimpurityspectroscopy of quasiparticlesinterpolaron correlationsquantum depletionultracold atoms |
| spellingShingle | Hiroyuki Tajima Junichi Takahashi Simeon I. Mistakidis Eiji Nakano Kei Iida Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium Atoms polaron impurity spectroscopy of quasiparticles interpolaron correlations quantum depletion ultracold atoms |
| title | Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium |
| title_full | Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium |
| title_fullStr | Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium |
| title_full_unstemmed | Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium |
| title_short | Polaron Problems in Ultracold Atoms: Role of a Fermi Sea across Different Spatial Dimensions and Quantum Fluctuations of a Bose Medium |
| title_sort | polaron problems in ultracold atoms role of a fermi sea across different spatial dimensions and quantum fluctuations of a bose medium |
| topic | polaron impurity spectroscopy of quasiparticles interpolaron correlations quantum depletion ultracold atoms |
| url | https://www.mdpi.com/2218-2004/9/1/18 |
| work_keys_str_mv | AT hiroyukitajima polaronproblemsinultracoldatomsroleofafermiseaacrossdifferentspatialdimensionsandquantumfluctuationsofabosemedium AT junichitakahashi polaronproblemsinultracoldatomsroleofafermiseaacrossdifferentspatialdimensionsandquantumfluctuationsofabosemedium AT simeonimistakidis polaronproblemsinultracoldatomsroleofafermiseaacrossdifferentspatialdimensionsandquantumfluctuationsofabosemedium AT eijinakano polaronproblemsinultracoldatomsroleofafermiseaacrossdifferentspatialdimensionsandquantumfluctuationsofabosemedium AT keiiida polaronproblemsinultracoldatomsroleofafermiseaacrossdifferentspatialdimensionsandquantumfluctuationsofabosemedium |