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Related papers: Quantum fluctuations stabilize Skyrmion textures

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Skyrmions are topological solitons that emerge in many physical contexts. In magnetism, they appear as textures of the spin-density field stabilized by different competing interactions and characterized by a topological charge that counts…

Mesoscale and Nanoscale Physics · Physics 2020-01-15 Hector Ochoa , Yaroslav Tserkovnyak

The discussion of vacuum energy is currently a subject of great theoretical importance, specially concerning the cosmological constant problem in General Relativity. From Quantum Field Theory, it is stated that vacuum states subject to…

High Energy Physics - Theory · Physics 2020-02-07 A. P. C. M. Lima , G. Alencar , C. R. Muniz , R. R. Landim

In this work, we present a rather simple method to study the Casimir effect on a spherical shell for a massless scalar field with Dirichlet boundary condition by applying the indefinite metric field (Krein) quantization technique. In this…

Mathematical Physics · Physics 2018-08-16 H. Pejhan , M. Reza Tanhayi , M. V. Takook

A combined approach using first-principles calculations and spin dynamics simulations is applied to study Ni/Ir$_{n}$/Pt(111) ($n=0,1,2$) films. The lowest-energy states are predicted to be spin-spirals but with a minute (of the order of a…

Materials Science · Physics 2021-11-23 P. C. Carvalho , I. P. Miranda , A. B. Klautau , A. Bergman , H. M. Petrilli

Magnetic excitations in ferromagnetic systems with a noncollinear ground state magnetization experience a fictitious magnetic field due to the equilibrium magnetic texture. Here, we investigate how such fictitious fields lead to thermal…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 Kevin A. van Hoogdalem , Yaroslav Tserkovnyak , Daniel Loss

Magnetic skyrmions have the potential to provide solutions for low-power, high-density data storage and processing. One of the major challenges in developing skyrmion-based devices is the skyrmions' magnetic stability in confined…

When magnetic skyrmions are moved via currents, they do not strictly travel along the path of the current, instead their motion also gains a transverse component. This so-called skyrmion Hall effect can be detrimental in potential skyrmion…

Mesoscale and Nanoscale Physics · Physics 2022-01-27 Jonas Spethmann , Elena Y. Vedmedenko , Roland Wiesendanger , André Kubetzka , Kirsten von Bergmann

Charged particles exhibit the Hall effect in the presence of magnetic fields. Analogously, ferromagnetic skyrmions with non-zero topological charges and finite fictitious magnetic fields exhibit the skyrmion Hall effect, which is…

We study the stabilization and electrical manipulation of skyrmions in magnetic ultrathin films in the absence of an applied magnetic field. We show that this requires an increased magnetic anisotropy, controlled by the sample thickness, as…

Materials Science · Physics 2023-01-06 Sougata Mallick , Sujit Panigrahy , Gajanan Pradhan , Stanislas Rohart

We calculate the Casimir energy for scalar and gauge fields in interaction with zero-width mirrors, including quantum effects due to the matter fields inside the mirrors. We consider models where those fields are either scalar or fermionic,…

High Energy Physics - Theory · Physics 2008-11-26 C. D. Fosco , F. C. Lombardo , F. D. Mazzitelli

We show the presence of a Casimir type force between domain walls in a two dimensional Heisenberg antiferromagnet subject to geometrical fluctuations. The type of fluctuations that we consider, called phason flips, are well known in…

Strongly Correlated Electrons · Physics 2013-03-22 Anuradha Jagannathan , Attila Szallas

Zero-point energy is generally known to be unphysical. Casimir effect, however, is often presented as a counterexample, giving rise to a conceptual confusion. To resolve the confusion we study foundational aspects of Casimir effect at a…

Quantum Physics · Physics 2017-08-23 H. Nikolic

For a Friedman-Robertson-Walker space-time in which the only contribution to the stress-energy tensor comes from the renormalised zero-point energy (i.e. the Casimir energy) of the fundamental fields the evolution of the universe (the scale…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Frank Antonsen , Karsten Bormann

We study the zero point energy of massless scalar and vector fields subject to spheroidal boundary conditions. For massless scalar fields and small ellipticity the zero-point energy can be found using both zeta function and Green's function…

Quantum Physics · Physics 2015-05-20 A. R. Kitson , A. I. Signal

In this paper, we use the formalism of finite-temperature quantum field theory to investigate the Casimir force between flat, ideally conductive surfaces containing confined, but mobile ions. We demonstrate that, in the Gaussian…

Quantum Physics · Physics 2025-04-24 Yu. A. Budkov , P. E. Brandyshev

The Casimir effect has been studied for various quantum fields in both flat and curved spacetimes. As a further step along this line, we provide an explicit derivation of Casimir effect for massless spin-3/2 field with periodic boundary…

High Energy Physics - Theory · Physics 2009-03-19 Wenbiao Liu , Kui Xiao , Hongbao Zhang

The Casimir effect results from alterations of the zero-point electromagnetic energy introduced by boundary-conditions. For ferromagnetic layers separated by vacuum (or a dielectric) such boundary-conditions are influenced by the…

Quantum Physics · Physics 2009-11-07 G. Metalidis , P. Bruno

We provide a review of both new experimental and theoretical developments in the Casimir effect. The Casimir effect results from the alteration by the boundaries of the zero-point electromagnetic energy. Unique to the Casimir force is its…

Quantum Physics · Physics 2008-11-26 M. Bordag , U. Mohideen , V. M. Mostepanenko

Fluctuation-induced forces, primarily represented by quantum and critical Casimir effects, play a pivotal role at the nanoscale. This review explores the theoretical and experimental landscapes of these forces, offering a comprehensive…

Quantum Physics · Physics 2025-05-21 Roberto Passante , Lucia Rizzuto , Peter Schall , Emanuele Marino

In discussions of the cosmological constant, the Casimir effect is often invoked as decisive evidence that the zero point energies of quantum fields are "real''. On the contrary, Casimir effects can be formulated and Casimir forces can be…

High Energy Physics - Theory · Physics 2009-11-11 R. L. Jaffe