Quantum critical thermal transport in the unitary Fermi gas
Strongly correlated systems are often associated with an underlying quantum critical point which governs their behavior in the finite-temperature phase diagram. Their thermodynamical and transport properties arise from critical fluctuations and follow universal scaling laws. Here, we develop a micro...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
American Physical Society
2020-06-01
|
| Series: | Physical Review Research |
| Online Access: | http://doi.org/10.1103/PhysRevResearch.2.023301 |
| _version_ | 1797211405224509440 |
|---|---|
| author | Bernhard Frank Wilhelm Zwerger Tilman Enss |
| author_facet | Bernhard Frank Wilhelm Zwerger Tilman Enss |
| author_sort | Bernhard Frank |
| collection | DOAJ |
| description | Strongly correlated systems are often associated with an underlying quantum critical point which governs their behavior in the finite-temperature phase diagram. Their thermodynamical and transport properties arise from critical fluctuations and follow universal scaling laws. Here, we develop a microscopic theory of thermal transport in the quantum critical regime expressed in terms of a thermal sum rule and an effective scattering time. We explicitly compute the characteristic scaling functions in a quantum critical model system, the unitary Fermi gas. Moreover, we derive an exact thermal sum rule for heat and energy currents and evaluate it numerically using the nonperturbative Luttinger-Ward approach. For the thermal scattering times we find a simple quantum critical scaling form. Together, the sum rule and the scattering time determine the heat conductivity, thermal diffusivity, Prandtl number, and sound diffusivity from high temperatures down into the quantum critical regime. The results provide a quantitative description of recent sound attenuation measurements in ultracold Fermi gases. |
| first_indexed | 2024-04-24T10:25:58Z |
| format | Article |
| id | doaj.art-74dab66c5a02430595c01342cea79746 |
| institution | Directory Open Access Journal |
| issn | 2643-1564 |
| language | English |
| last_indexed | 2024-04-24T10:25:58Z |
| publishDate | 2020-06-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review Research |
| spelling | doaj.art-74dab66c5a02430595c01342cea797462024-04-12T16:55:13ZengAmerican Physical SocietyPhysical Review Research2643-15642020-06-012202330110.1103/PhysRevResearch.2.023301Quantum critical thermal transport in the unitary Fermi gasBernhard FrankWilhelm ZwergerTilman EnssStrongly correlated systems are often associated with an underlying quantum critical point which governs their behavior in the finite-temperature phase diagram. Their thermodynamical and transport properties arise from critical fluctuations and follow universal scaling laws. Here, we develop a microscopic theory of thermal transport in the quantum critical regime expressed in terms of a thermal sum rule and an effective scattering time. We explicitly compute the characteristic scaling functions in a quantum critical model system, the unitary Fermi gas. Moreover, we derive an exact thermal sum rule for heat and energy currents and evaluate it numerically using the nonperturbative Luttinger-Ward approach. For the thermal scattering times we find a simple quantum critical scaling form. Together, the sum rule and the scattering time determine the heat conductivity, thermal diffusivity, Prandtl number, and sound diffusivity from high temperatures down into the quantum critical regime. The results provide a quantitative description of recent sound attenuation measurements in ultracold Fermi gases.http://doi.org/10.1103/PhysRevResearch.2.023301 |
| spellingShingle | Bernhard Frank Wilhelm Zwerger Tilman Enss Quantum critical thermal transport in the unitary Fermi gas Physical Review Research |
| title | Quantum critical thermal transport in the unitary Fermi gas |
| title_full | Quantum critical thermal transport in the unitary Fermi gas |
| title_fullStr | Quantum critical thermal transport in the unitary Fermi gas |
| title_full_unstemmed | Quantum critical thermal transport in the unitary Fermi gas |
| title_short | Quantum critical thermal transport in the unitary Fermi gas |
| title_sort | quantum critical thermal transport in the unitary fermi gas |
| url | http://doi.org/10.1103/PhysRevResearch.2.023301 |
| work_keys_str_mv | AT bernhardfrank quantumcriticalthermaltransportintheunitaryfermigas AT wilhelmzwerger quantumcriticalthermaltransportintheunitaryfermigas AT tilmanenss quantumcriticalthermaltransportintheunitaryfermigas |