scholarly journals Deconfinement of electric charges in hydrogen-bonded ferroelectrics

2017 ◽  
Vol 31 (20) ◽  
pp. 1750130 ◽  
Author(s):  
Bo-Jie Huang ◽  
Chyh-Hong Chern
Keyword(s):  
Gauge Theory ◽  
Electric Charge ◽  
Degree Of Freedom ◽  
Dielectric Susceptibility ◽  
Charge Degree ◽  
Charge Degree Of Freedom ◽  
Hydrogen Bonded

In addition to the gauge charges, a new charge degree of freedom is identified in the deconfined phase in the lattice Ising gauge theory. While applying to the hydrogen-bonded ferroelectrics, the new charge is essentially the electric charge, leading to the divergent dielectric susceptibility. The new degree of freedom paves an experimentally accessible way to identify the deconfined phase in the lattice Ising gauge theory.

scholarly journals Twist engineering of the two-dimensional magnetism in double bilayer chromium triiodide homostructures

2021 ◽  
Author(s):  
Hongchao Xie ◽  
Xiangpeng Luo ◽  
Gaihua Ye ◽  
Zhipeng Ye ◽  
Haiwen Ge ◽  
...  
Keyword(s):  
Twist Angle ◽  
Degree Of Freedom ◽  
Two Dimensional ◽  
Magnetic Ground State ◽  
Linear Superposition ◽  
Experimental Realization ◽  
Spin Degree ◽  
Charge Degree ◽  
Ising Magnet ◽  
Charge Degree Of Freedom

Abstract Twist engineering, or the alignment of two-dimensional (2D) crystalline layers with desired orientations, has led to tremendous success in modulating the charge degree of freedom in hetero- and homo-structures, in particular, in achieving novel correlated and topological electronic phases in moiré electronic crystals. However, although pioneering theoretical efforts have predicted nontrivial magnetism and magnons out of twisting 2D magnets, experimental realization of twist engineering spin degree of freedom remains elusive. Here, we leverage the archetypal 2D Ising magnet chromium triiodide (CrI3) to fabricate twisted double bilayer homostructures with tunable twist angles and demonstrate the successful twist engineering of 2D magnetism in them. Using linear and circular polarization-resolved Raman spectroscopy, we identify magneto-Raman signatures of a new magnetic ground state that is sharply distinct from those in natural bilayer (2L) and four-layer (4L) CrI3. With careful magnetic field and twist angle dependence, we reveal that, for a very small twist angle (~ 0.5 degree), this emergent magnetism can be well-approximated by a weighted linear superposition of those of 2L and 4L CI3 whereas, for a relatively large twist angle (~ 5 degree), it mostly resembles that of isolated 2L CrI3. Remarkably, at an intermediate twist angle (~ 1.1 degree), its magnetism cannot be simply inferred from the 2L and 4L cases, because it lacks sharp spin-flip transitions that are present in 2L and 4L CrI3 and features a dramatic Raman circular dichroism that is absent in natural 2L and 4L ones. Our results demonstrate the possibility of designing and controlling the spin degree of freedom in 2D magnets using twist engineering.

Charge degree of freedom as a sensitive probe for fission mechanism

1997 ◽  
Vol 223 (1-2) ◽  
pp. 99-119
Author(s):  
A. Yokoyama ◽  
H. Baba ◽  
N. Takahashi ◽  
M.-C. Duh ◽  
T. Saito
Keyword(s):  
Degree Of Freedom ◽  
Charge Degree ◽  
Charge Degree Of Freedom

scholarly journals New directions in spintronics

2011 ◽  
Vol 369 (1948) ◽  
pp. 3027-3036 ◽  
Author(s):  
C. H. Marrows ◽  
B. J. Hickey
Keyword(s):  
Solid State ◽  
External Field ◽  
Electron Spin ◽  
Degree Of Freedom ◽  
Spin Degree ◽  
Magnetic Components ◽  
New Directions ◽  
Excellent Candidate ◽  
Charge Degree ◽  
Charge Degree Of Freedom

Conventional microelectronics exploits only the charge degree of freedom of the electron. Bringing the spin degree of freedom to bear on sensing, radio frequency, memory and logic applications opens up new possibilities for ‘more than Moore’ devices incorporating magnetic components that can couple to an external field, store a bit of data or represent a Boolean state. Moreover, the electron spin is an archetypal two-state quantum system that is an excellent candidate for a solid-state realization of a qubit.

The front-form Hamiltonian and BRST formulations of the Nielsen–Olesen model in the broken symmetry phase

2004 ◽  
Vol 82 (7) ◽  
pp. 569-583 ◽  
Author(s):  
Usha Kulshreshtha ◽  
D S Kulshreshtha
Keyword(s):  
Matter Field ◽  
Degree Of Freedom ◽  
Broken Symmetry ◽  
Time Dimension ◽  
Symmetry Phase ◽  
Front Form ◽  
Charge Degree ◽  
Complex Matter ◽  
Charge Degree Of Freedom

The front-form Hamiltonian and BRST formulations of the Nielsen–Olesen model are investigated in two-space one-time dimension in the broken (frozen) symmetry phase, where the phase ϕ(xμ) of the complex matter field Φ(xμ) carries the charge degree of freedom of the complex matter field and is, in fact, akin to the Goldstone Boson.PACS No.: 11.15.–q

scholarly journals Charge Degree of Freedom and the Single-Spin Fluid Model inYBa2Cu4O8

2000 ◽  
Vol 84 (21) ◽  
pp. 4938-4941 ◽  
Author(s):  
A. Suter ◽  
M. Mali ◽  
J. Roos ◽  
D. Brinkmann
Keyword(s):  
Fluid Model ◽  
Degree Of Freedom ◽  
Single Spin ◽  
Charge Degree ◽  
Charge Degree Of Freedom ◽  
Spin Fluid

Functional Transition Metal Perovskite Oxides with 6s2 Lone Pair Activity Stabilized by High-Pressure Synthesis

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Masaki Azuma ◽  
Hajime Hojo ◽  
Kengo Oka ◽  
Hajime Yamamoto ◽  
Keisuke Shimizu ◽  
...  
Keyword(s):  
High Pressure ◽  
Transition Metal ◽  
Transition Metals ◽  
Lone Pair ◽  
Degree Of Freedom ◽  
Publication Date ◽  
High Pressure Synthesis ◽  
Pressure Synthesis ◽  
Charge Degree ◽  
Charge Degree Of Freedom

Perovskite ABO3 oxides that have Bi and Pb at the A site and transition metals at the B site, when stabilized by high-pressure synthesis at several gigapascals, provide a rich parameter space of fascinating properties. Stereochemical 6 s2 lone pairs of Bi3+ and Pb2+ induce polar or antipolar distortions. 6 s2 and 6 s0 (Bi5+ and Pb4+) charge degree of freedom enable intermetallic charge transfer transitions. The structural distortion and the charge degree of freedom are coupled with magnetism of transition metals, resulting in various functionalities. In particular, we highlight magnetization reversal by electric field and polarization rotation in BiFe1− xCo xO3, negative thermal expansion in modified BiNiO3 and PbVO3, and systematic charge distribution changes in Pb MO3 ( M = 3 d transition metal). Expected final online publication date for the Annual Review of Materials Science, Volume 51 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals GAUGE INVARIANT DRESSED HOLON AND SPINON IN DOPED CUPRATES

2003 ◽  
Vol 17 (09) ◽  
pp. 361-373 ◽  
Author(s):  
SHIPING FENG ◽  
TIANXING MA ◽  
JIHONG QIN
Keyword(s):  
Charge Transport ◽  
Hard Core ◽  
Degree Of Freedom ◽  
Gauge Invariant ◽  
Spin Degree ◽  
Novel Approach ◽  
Spin Response ◽  
Underdoped Cuprates ◽  
Charge Degree ◽  
Charge Degree Of Freedom

We develop a partial charge-spin separation fermion-spin theory implemented by the gauge invariant dressed holon and spinon. In this novel approach, the physical electron is decoupled as the gauge invariant dressed holon and spinon, with the dressed holon behaviors like a spinful fermion, and represents the charge degree of freedom together with the phase part of the spin degree of freedom, while the dressed spinon is a hard-core boson, and represents the amplitude part of the spin degree of freedom, then the electron single occupancy local constraint is satisfied. Within this approach, the charge transport and spin response of the underdoped cuprates is studied. It is shown that the charge transport is mainly governed by the scattering from the dressed holons due to the dressed spinon fluctuation, while the scattering from the dressed spinons due to the dressed holon fluctuation dominates the spin response.

scholarly journals Dirac equation based on the vector representation of the Lorentz group

2020 ◽  
Vol 135 (10) ◽  
Author(s):  
Eckart Marsch ◽  
Yasuhito Narita
Keyword(s):  
Gauge Theory ◽  
Dirac Equation ◽  
Lorentz Group ◽  
Degrees Of Freedom ◽  
Lagrangian Density ◽  
Degree Of Freedom ◽  
Vector Representation ◽  
Massive Fermion

AbstractIn this paper, we derive an expanded Dirac equation for a massive fermion doublet, which has in addition to the particle/antiparticle and spin-up/spin-down degrees of freedom explicity an isospin-type degree of freedom. We begin with revisiting the four-vector Lorentz group generators, define the corresponding gamma matrices and then write a Dirac equation for the fermion doublet with eight spinor components. The appropriate Lagrangian density is established, and the related chiral and SU(2) symmetry is discussed in detail, as well as applications to an electroweak-style gauge theory. In “Appendix,” we present some of the relevant matrices.

scholarly journals Origin of Gauge Theories in Electrodynamics

2021 ◽  
Author(s):  
Jay Solanki
Keyword(s):  
Field Theory ◽  
Electromagnetic Field ◽  
Gauge Theory ◽  
Gauge Invariance ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Gauge Theories ◽  
Degree Of Freedom ◽  
Potential Formulation ◽  
Electromagnetic Field Theory

<div>The potential formulation has significant advantages over field formulation in solving complicated problems in electromagnetic field theory. One essential part of electromagnetic field theory's potential formulation is gauge invariance and gauge theories because it provides an extra degree of freedom. By using this extra degree of freedom, we can solve complicated electromagnetic problems quickly. Thus, it is necessary to include a systematic explanation of gauge theories in teaching electromagnetic theory. However, textbooks usually formulate gauge theories by using Maxwell's equations of electromagnetism, by using vector calculus identities. However, this method of formulation of gauge theories does not give a clear idea about the origin of gauge theories and gauge invariance in electromagnetism. Here the author formulates gauge theories from wave equations of the electric and magnetic fields instead of directly using Maxwell's equations. This method generalizes all gauge theories like Lorenz gauge theory, Coulomb gauge theory, Etc. Gauge theory, because of the way the author derives it, gives a distinct idea about the mathematical origin of the gauge theories and gauge invariance in electromagnetic field theory. Thus, the author reviews the origin of gauge theories in electromagnetic field theory and develops a distinct and effective method to introduce gauge theory in the teaching of electromagnetic field theory that can provide better understanding of the topic to undergraduate students.</div><div><br></div>

Sign in / Sign up

Export Citation Format

Share Document