Article
Astronomy & Astrophysics
Katsumasa Nakayama, Kei Suzuki
Summary: The Casimir effect is a quantum phenomenon caused by the zero-point energy of relativistic fields in a finite-size system. While this effect has been extensively studied in photon fields, its counterpart in fermion fields in Dirac/Weyl semimetals remains an open question. In this study, we theoretically demonstrate the characteristics of the Casimir effect in relativistic electron fields in Dirac/Weyl semimetals, using an effective Hamiltonian for realistic materials such as Cd3As2 and Na3Bi. We observe an oscillation of the Casimir energy with the thickness of the thin film, which is attributed to the existence of Dirac/Weyl nodes in momentum space. This effect can be experimentally observed in thin films of semimetals, where the thickness-dependent thermodynamic quantities are influenced by the Casimir energy.
Article
Astronomy & Astrophysics
Aram Saharian, Tigran Petrosyan, Arshak Hovhannisyan
Summary: The study focuses on the fermion condensate in a truncated cone with different boundary conditions. The condensate is an even periodic function of magnetic flux, and can be positive or negative depending on the boundary conditions. In a boundary-free conical geometry, the condensate vanishes and nonzero contributions are purely edge-induced effects.
Article
Materials Science, Multidisciplinary
Gideon Lee, Aleksandr Rodin
Summary: The study introduces a general method for calculating the Helmholtz free energy due to vibrational modes in systems of varying dimensionality and composition, enabling the extraction of defect interaction energy between different defect configurations at different temperatures. The effectiveness of the approach is demonstrated through numerical calculations and validation using exact diagonalization.
Article
Physics, Multidisciplinary
Kouki Nakata, Kei Suzuki
Summary: Quantum fluctuations, key concepts of quantum mechanics, induce a zero-point energy shift known as the Casimir effect. This phenomenon has attracted attention in various fields, from elementary particle physics to condensed matter physics and photonics. While yttrium iron garnet (YIG) has been extensively studied for spintronics, the application of the Casimir effect to ferrimagnetic thin films has not been explored enough. In this study, using lattice field theory, we investigate the Casimir effect on magnons in insulating magnets and find that it can arise in ferrimagnetic YIG thin films. Our results suggest that YIG can serve as a promising platform for Casimir engineering in magnon-based spintronics.
PHYSICAL REVIEW LETTERS
(2023)
Review
Physics, Multidisciplinary
D. M. Dantchev, S. Dietrich
Summary: Introduces the influence of temperature fluctuations and quantum nature on the properties of material in different media, as well as the modifications of the surrounding medium caused by the shape and properties of the material. It mentions the concept of the Casimir force, which is the force between bodies caused by the excitation of the medium. The focus is on the critical Casimir effect, which is the force between bodies due to fluctuations in the order parameter near the critical point. It presents the exact results of the critical Casimir effect in different models and geometries.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2023)
Article
Astronomy & Astrophysics
Francesco Sorge
Summary: This study investigates the influence of a time-varying spacetime background on the vacuum polarization of a massless quantum field confined to a Casimir cavity. The background is modeled as an anisotropic Bianchi-I spacetime, and using Schwinger's proper-time approach, the vacuum polarization inside the Casimir cavity is evaluated. The results show a small shift in the field vacuum energy once the perturbation is over, indicating that the time-dependent background distorts the field modes and causes a permanent change in the zero-point energy of the field confined to the Casimir apparatus.
Article
Physics, Multidisciplinary
Xingyu Guo, Jiaxing Zhao, Pengfei Zhuang
Summary: In this study, we investigated the Casimir effect in equilibrium and non-equilibrium photon gas under the U(1) gauge field using quantum kinetic theory. We derived the transport, constraint, and gauge fixing equations for the photon number distribution from Maxwell's equations. The energy variation and Casimir force for a finite system considering the boundary condition were also calculated. The results showed that the Casimir force in equilibrium state is suppressed by the thermal motion of photons when considering two adiabatic plates. In a non-equilibrium state, the photon-induced Casimir force oscillates and decays with time, eventually disappearing.
NEW JOURNAL OF PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Zhujing Xu, Xingyu Gao, Jaehoon Bang, Zubin Jacob, Tongcang Li
Summary: The study explores the non-reciprocal energy transfer phenomenon caused by quantum vacuum fluctuations, demonstrating strong coupling between two micromechanical oscillators through modulation of Casimir interaction parameters, leading to non-reciprocal energy transfer.
NATURE NANOTECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Mehrdokht Sasanpour, Chonoor Ajilyan, Siamak S. Gousheh
Summary: We calculate the Casimir thermodynamic quantities for a massive fermion field between two parallel plates with the MIT boundary conditions using three different general approaches. We provide explicit solutions for each approach and show that they are not equivalent and generally yield different results. The first approach in particular yields Casimir thermodynamic quantities that go to zero as the temperature, mass of the field, or distance between the plates increases.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Materials Science, Multidisciplinary
Zi-Ang Hu, Huan-Wen Wang, Bo Fu, Jin-Yu Zou, Shun-Qing Shen
Summary: Parity anomaly is a quantum mechanical effect where the parity symmetry in a two-dimensional classical action is not restored in any regularization of the full quantum theory, resulting in a half-quantized Hall conductivity. This study proposes a scheme to experimentally explore the signature of parity anomaly in the measurement of optical Hall conductivity.
Article
Materials Science, Multidisciplinary
Debabrata Sinha
Summary: The study investigates the effects of time-reversal symmetric or broken tilt in an inversion asymmetric Weyl semimetal Josephson junction, revealing the occurrence of Josephson 0-π transition and zero-bias valley/chiral supercurrent. Additionally, it demonstrates the emergence of pure valley Josephson current and pure chirality Josephson current due to the respective tilts, leading to controllable reversal of VJC and CJC even in the zero-bias condition. This tilt-induced Josephson effect provides an alternative pathway for supercurrent 0-π transition, with VJC and CJC associated with a quantum anomaly in the absence of TRS and TRS breaking tilts in the long junction and zero-temperature limit.
Article
Physics, Multidisciplinary
Thorsten Emig, Giuseppe Bimonte
Summary: Recent measurements of Casimir forces have shown that quantum fluctuations of the electromagnetic field undergo intricate modifications in complex geometries. In this paper, a multiple scattering description is introduced for calculating Casimir interactions between bodies of arbitrary shape and material composition. This approach allows for the calculation of interactions in complex geometries using just a few wave scatterings, without any prior knowledge of the scattering amplitudes of the bodies. Some initial applications demonstrate the efficacy of this method.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Lanyi Xie, Fuwei Yang, Bai Song
Summary: By employing the Lifshitz theory, researchers have discovered a significant isotope effect of over 10-1 in polar dielectrics. This effect arises from the isotope-mass-induced line shift of the zone-center optical phonons and is insensitive to the linewidth. The three-orders-of-magnitude difference between polar dielectrics and metals is due to the distinct isotopic dependence of the phonon and plasma frequencies.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Article
Physics, Multidisciplinary
Tsutomu Ishikawa, Katsumasa Nakayama, Kei Suzuki
Summary: The Casimir effect is caused by the zero-point energy of particles deformed by the existence of two parallel plates. By studying lattice fermions in different dimensional spacetimes, such as the naive fermion, Wilson fermion, and overlap fermion, the oscillatory behavior of Casimir energy between odd and even lattice sizes is observed, induced by contributive ultraviolet-momentum modes.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Astronomy & Astrophysics
Claudio Borquez, Byron Droguett
Summary: In this study, we investigate the Casimir effect of a membrane embedded in a 2 + 1-dimensional flat cone generated by a massive particle located at the origin. The flat cone is an exact solution of the nonprojectable Horava theory, similar to general relativity. We consider a scalar field satisfying Dirichlet boundary conditions and use the ζ-function technique for spectral regularization. Additionally, we incorporate the effects of temperature. Our findings demonstrate that the Casimir force depends on three factors: the anisotropic scaling z, the mass of the point particle, and the temperature.
