Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport
Abstract Due to the spin-orbit coupling, Dirac fermions, submerged in a thermal bath with finite macroscopic vorticity, exhibit a spin polarisation along the direction parallel to the vorticity vector $$\varvec{\Omega }$$ Ω . Due to the symmetries of the Lagrangian for free massless Dirac particles,...
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| Language: | English |
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SpringerOpen
2024-12-01
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| Series: | European Physical Journal C: Particles and Fields |
| Online Access: | https://doi.org/10.1140/epjc/s10052-024-13713-6 |
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| author | Sergio Morales-Tejera Victor E. Ambruş Maxim N. Chernodub |
| author_facet | Sergio Morales-Tejera Victor E. Ambruş Maxim N. Chernodub |
| author_sort | Sergio Morales-Tejera |
| collection | DOAJ |
| description | Abstract Due to the spin-orbit coupling, Dirac fermions, submerged in a thermal bath with finite macroscopic vorticity, exhibit a spin polarisation along the direction parallel to the vorticity vector $$\varvec{\Omega }$$ Ω . Due to the symmetries of the Lagrangian for free massless Dirac particles, there are three independent and classically conserved currents corresponding to the vector, axial, and helical charges. The constitutive relations for the charge currents and the stress-energy tensor at thermal equilibrium, derived in the framework of quantum field theory at finite temperature, reveal vorticity-induced contributions that deviate from the perfect fluid form. In this paper, we consider the mode structure of the corresponding hydrodynamical theory and derive collective excitations associated with coherent fluctuations of all three charges. We show that the chirally imbalanced rotating fluid should possess non-reciprocal gapless waves that propagate with different velocities along and opposite to the vorticity vector. We also uncover a strictly unidirectional mode, which we call the axial vortical wave, propagating in the background of the axial charge density. The emergence of this wave can be traced back to earlier studies of vortical chiral fluids in a hydrodynamic approach. We also point out an unexpected instability in the limit of degenerate matter and discuss possible solutions when helicity and axial charge non-conservation are taken into account. |
| format | Article |
| id | doaj-art-d582bd89e7a944908f72d2115cb8688a |
| institution | Kabale University |
| issn | 1434-6052 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | European Physical Journal C: Particles and Fields |
| spelling | doaj-art-d582bd89e7a944908f72d2115cb8688a2025-02-02T12:39:02ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60522024-12-01841212910.1140/epjc/s10052-024-13713-6Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transportSergio Morales-Tejera0Victor E. Ambruş1Maxim N. Chernodub2Department of Physics, West University of TimişoaraDepartment of Physics, West University of TimişoaraDepartment of Physics, West University of TimişoaraAbstract Due to the spin-orbit coupling, Dirac fermions, submerged in a thermal bath with finite macroscopic vorticity, exhibit a spin polarisation along the direction parallel to the vorticity vector $$\varvec{\Omega }$$ Ω . Due to the symmetries of the Lagrangian for free massless Dirac particles, there are three independent and classically conserved currents corresponding to the vector, axial, and helical charges. The constitutive relations for the charge currents and the stress-energy tensor at thermal equilibrium, derived in the framework of quantum field theory at finite temperature, reveal vorticity-induced contributions that deviate from the perfect fluid form. In this paper, we consider the mode structure of the corresponding hydrodynamical theory and derive collective excitations associated with coherent fluctuations of all three charges. We show that the chirally imbalanced rotating fluid should possess non-reciprocal gapless waves that propagate with different velocities along and opposite to the vorticity vector. We also uncover a strictly unidirectional mode, which we call the axial vortical wave, propagating in the background of the axial charge density. The emergence of this wave can be traced back to earlier studies of vortical chiral fluids in a hydrodynamic approach. We also point out an unexpected instability in the limit of degenerate matter and discuss possible solutions when helicity and axial charge non-conservation are taken into account.https://doi.org/10.1140/epjc/s10052-024-13713-6 |
| spellingShingle | Sergio Morales-Tejera Victor E. Ambruş Maxim N. Chernodub Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport European Physical Journal C: Particles and Fields |
| title | Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport |
| title_full | Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport |
| title_fullStr | Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport |
| title_full_unstemmed | Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport |
| title_short | Vortical waves in a quantum fluid with vector, axial, and helical charges. I. Non-dissipative transport |
| title_sort | vortical waves in a quantum fluid with vector axial and helical charges i non dissipative transport |
| url | https://doi.org/10.1140/epjc/s10052-024-13713-6 |
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