scholarly journals Evidence for solitonic spin excitations from a charge-lattice–coupled ferroelectric order

2018 ◽  
Vol 4 (11) ◽  
pp. eaau7725 ◽  
Author(s):  
K. Sunami ◽  
T. Nishikawa ◽  
K. Miyagawa ◽  
S. Horiuchi ◽  
R. Kato ◽  
...  
Keyword(s):  
Relaxation Rate ◽  
Particle Physics ◽  
Degrees Of Freedom ◽  
Condensed Matter ◽  
Topological Defects ◽  
Spectral Shift ◽  
Nmr Study ◽  
Spin Singlet ◽  
Spin Excitations ◽  
Ferroelectric Order

Topological defects have been explored in different fields ranging from condensed matter physics and particle physics to cosmology. In condensed matter, strong coupling between charge, spin, and lattice degrees of freedom brings about emergent excitations with topological characteristics at low energies. One-dimensional (1D) systems with degenerate dimerization patterns are typical stages for the generation of topological defects, dubbed “solitons”; for instance, charged solitons are responsible for high electrical conductivity in doped trans-polyacetylene. Here, we provide evidence based on a nuclear magnetic resonance (NMR) study for mobile spin solitons deconfined from a strongly charge-lattice–coupled spin-singlet ferroelectric order in a quasi-1D organic charge-transfer complex. The NMR spectral shift and relaxation rate associated with static and dynamic spin susceptibilities indicate that the ferroelectric order is violated by dilute solitonic spin excitations, which were further demonstrated to move diffusively by the frequency dependence of the relaxation rate. The traveling solitons revealed here may promise the emergence of anomalous electrical and thermal transport.

scholarly journals Phase Transitions and Topological Defects in the Early Universe

1997 ◽  
Vol 50 (4) ◽  
pp. 697 ◽  
Author(s):  
T. W. B. Kibble
Keyword(s):  
Phase Transitions ◽  
Low Temperature ◽  
Early Universe ◽  
Particle Physics ◽  
Defect Density ◽  
Cosmic Strings ◽  
Condensed Matter ◽  
Topological Defects ◽  
Helium 3 ◽  
The Universe

Our present theories of particle physics and cosmology, taken together, suggest that very early in its history, the universe underwent a series of phase transitions, at which topological defects, similar to those formed in some condensed matter transitions, may have been created. Such defects, in particular cosmic strings, may survive long enough to have important observable effects in the universe today. Predicting these effects requires us to estimate the initial defect density and the way that defects subsequently evolve. Very similar problems arise in condensed matter systems, and recently it has been possible to test some of our ideas about the formation of defects using experiments with liquid helium-3 (in collaboration with the Low Temperature Laboratory in Helsinki). I shall review the present status of this theory.

scholarly journals Introduction. Cosmology meets condensed matter

2008 ◽  
Vol 366 (1877) ◽  
pp. 2793-2802 ◽  
Author(s):  
T.W.B Kibble ◽  
G.R Pickett
Keyword(s):  
Field Theory ◽  
Low Temperature ◽  
Particle Physics ◽  
Royal Society ◽  
Condensed Matter ◽  
Topological Defects ◽  
European Science Foundation ◽  
European Science ◽  
The Subject ◽  
Early Universe Cosmology

At first sight, low-temperature condensed-matter physics and early Universe cosmology seem worlds apart. Yet, in the last few years a remarkable synergy has developed between the two. It has emerged that, in terms of their mathematical description, there are surprisingly close parallels between them. This interplay has been the subject of a very successful European Science Foundation (ESF) programme entitled COSLAB (‘Cosmology in the Laboratory’) that ran from 2001 to 2006, itself built on an earlier ESF network called TOPDEF (‘Topological Defects: Non-equilibrium Field Theory in Particle Physics, Condensed Matter and Cosmology’). The articles presented in this issue of Philosophical Transactions A are based on talks given at the Royal Society Discussion Meeting ‘Cosmology meets condensed matter’, held on 28 and 29 January 2008. Many of the speakers had participated earlier in the COSLAB programme, but the strength of the field is illustrated by the presence also of quite a few new participants.

scholarly journals Multiorbital singlet pairing and d + d superconductivity

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Emilian M. Nica ◽  
Qimiao Si
Keyword(s):  
Time Reversal ◽  
Heavy Fermion ◽  
Degrees Of Freedom ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Matrix Structure ◽  
Spin Singlet ◽  
Low Energies ◽  
Triplet Pairing ◽  
Orbital Space

AbstractRecent experiments in multiband Fe-based and heavy-fermion superconductors have challenged the long-held dichotomy between simple s- and d-wave spin-singlet pairing states. Here, we advance several time-reversal-invariant irreducible pairings that go beyond the standard singlet functions through a matrix structure in the band/orbital space, and elucidate their naturalness in multiband systems. We consider the sτ3 multiorbital superconducting state for Fe-chalcogenide superconductors. This state, corresponding to a d + d intra- and inter-band pairing, is shown to contrast with the more familiar d + id state in a way analogous to how the B- triplet pairing phase of 3He superfluid differs from its A- phase counterpart. In addition, we construct an analog of the sτ3 pairing for the heavy-fermion superconductor CeCu2Si2, using degrees-of-freedom that incorporate spin-orbit coupling. Our results lead to the proposition that d-wave superconductors in correlated multiband systems will generically have a fully-gapped Fermi surface when they are examined at sufficiently low energies.

scholarly journals New applications of the renormalization group method in physics: a brief introduction

2011 ◽  
Vol 369 (1946) ◽  
pp. 2602-2611 ◽  
Author(s):  
Y. Meurice ◽  
R. Perry ◽  
S.-W. Tsai
Keyword(s):  
Renormalization Group ◽  
Phase Transitions ◽  
Dynamical Systems ◽  
Particle Physics ◽  
Recent Progress ◽  
Condensed Matter ◽  
Group Method ◽  
Renormalization Group Method ◽  
Theme Issue ◽  
New Applications

The renormalization group (RG) method developed by Ken Wilson more than four decades ago has revolutionized the way we think about problems involving a broad range of energy scales such as phase transitions, turbulence, continuum limits and bifurcations in dynamical systems. The Theme Issue provides articles reviewing recent progress made using the RG method in atomic, condensed matter, nuclear and particle physics. In the following, we introduce these articles in a way that emphasizes common themes and the universal aspects of the method.

scholarly journals A General Method for Transforming Nonphysical Configurations in BPS States

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
J. R. L. Santos ◽  
A. de Souza Dutra ◽  
O. C. Winter ◽  
R. A. C. Correa
Keyword(s):  
Scalar Field ◽  
Condensed Matter ◽  
Equations Of Motion ◽  
Cosmological Parameters ◽  
Topological Defects ◽  
Scalar Fields ◽  
Complex Scalar ◽  
Complex Scalar Field ◽  
Bps States ◽  
General Method

In this work, we apply the so-called BPS method in order to obtain topological defects for a complex scalar field Lagrangian introduced by Trullinger and Subbaswamy. The BPS approach led us to compute new analytical solutions for this model. In our investigation, we found analytical configurations which satisfy the BPS first-order differential equations but do not obey the equations of motion of the model. Such defects were named nonphysical ones. In order to recover the physical meaning of these defects, we proposed a procedure which can transform them into BPS states of new scalar field models. The new models here founded were applied in the context of hybrid cosmological scenarios, where we derived cosmological parameters compatible with the observed Universe. Such a methodology opens a new window to connect different two scalar fields systems and can be implemented in several distinct applications such as Bloch Branes, Lorentz and Symmetry Breaking Scenarios, Q-Balls, Oscillons, Cosmological Contexts, and Condensed Matter Systems.

scholarly journals TEV NEUTRINO PHYSICS AT THE LARGE HADRON COLLIDER

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3286-3296 ◽  
Author(s):  
ZHI-ZHONG XING
Keyword(s):  
Neutrino Physics ◽  
Large Hadron Collider ◽  
Particle Physics ◽  
Degrees Of Freedom ◽  
Neutrino Oscillations ◽  
Hadron Collider ◽  
Higgs Bosons ◽  
Type I ◽  
Seesaw Mechanism ◽  
Majorana Neutrinos

I argue that TeV neutrino physics might become an exciting frontier of particle physics in the era of the Large Hadron Collider (LHC). The origin of non-zero but tiny masses of three known neutrinos is probably related to the existence of some heavy degrees of freedom, such as heavy Majorana neutrinos or heavy Higgs bosons, via a TeV-scale seesaw mechanism. I take a few examples to illustrate how to get a balance between theoretical naturalness and experimental testability of TeV seesaws. Besides possible collider signatures at the LHC, new and non-unitary CP-violating effects are also expected to show up in neutrino oscillations for type-I, type-(I+II) and type-III seesaws at the TeV scale.

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