Reversible superconducting-normal phase transition in a magnetic field and the existence of topologically protected loop currents that appear and disappear without Joule heating

2020 ◽  
Vol 131 (3) ◽  
pp. 37001 ◽  
Author(s):  
Hiroyasu Koizumi
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Joule Heating ◽  
Normal Phase ◽  
Loop Currents

scholarly journals Phase-equilibrium of supraconductors in a magnetic field

1935 ◽  
Vol 152 (877) ◽  
pp. 650-663 ◽  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Phase Equilibrium ◽  
Electric Field ◽  
Transition Point ◽  
Normal Phase ◽  
Constant Current ◽  
Two Phase ◽  
Small Fields ◽  
Two Phases

At present it seems to be doubtful whether in the theory of supraconductivity the conception of two phases, a supraconducting and a normal phase, can describe the transformation between the two states and how far the equations which were first proposed for the pure supraconducting state in small fields remain true, when both phases are present. Especially it seems to be impossible to describe a phasetransition when an electric field is present, as probably occurs when one cools a wire carrying a constant current. However, where there is only a magnetic field the problem can be treated consistently, and the results are in agreement with experiment, and so it may be worth while to try the two-phase hypothesis, excluding equilibrium states in an electric field. The disturbance of supraconductivity by a magnetic field H T at a temperature t below the transition point has been treated thermodynamically by Gorter as a phase transition, the supraconducting phase being characterized by a zero value of the magnetic induction B

scholarly journals Magnetic-field effects on p-wave phase transition in Gauss–Bonnet gravity

2014 ◽  
Vol 29 (20) ◽  
pp. 1450094 ◽  
Author(s):  
Ya-Bo Wu ◽  
Jun-Wang Lu ◽  
Yong-Yi Jin ◽  
Jian-Bo Lu ◽  
Xue Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
P Wave ◽  
Vector Model ◽  
Magnetic Field Effects ◽  
Complex Vector ◽  
Bonnet Gravity ◽  
Yang Mills ◽  
Wave Phase ◽  
Lowest Landau Level

In the probe limit, we study the holographic p-wave phase transition in the Gauss–Bonnet gravity via numerical and analytical methods. Concretely, we study the influences of the external magnetic field on the Maxwell complex vector model in the five-dimensional Gauss–Bonnet–AdS black hole and soliton backgrounds, respectively. For the two backgrounds, the results show that the magnetic field enhances the superconductor phase transition in the case of the lowest Landau level, while the increasing Gauss–Bonnet parameter always hinders the vector condensate. Moreover, the Maxwell complex vector model is a generalization of the SU(2) Yang–Mills model all the time. In addition, the analytical results backup the numerical results. Furthermore, this model might provide a holographic realization for the QCD vacuum instability.

INFLUENCE OF AN EXTERNAL MAGNETIC FIELD ON THE DYNAMICS OF A NEW-PHASE NUCLEUS IN THE VICINITY OF THE FIRST-ORDER PHASE TRANSITION IN MAGNETS WITH DEFECTS PRESENT

2012 ◽  
Vol 26 (28) ◽  
pp. 1250183 ◽  
Author(s):  
VLADIMIR NAZAROV ◽  
RISHAT SHAFEEV
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
External Magnetic Field ◽  
Magnetic Anisotropy ◽  
Spin Reorientation ◽  
Critical Fields ◽  
First Order ◽  
Phase Nucleus ◽  
First Order Phase Transition ◽  
New Phase

Theoretically, with the aid of a soliton model, the evolution of a new-phase nucleus near the first-order spin-reorientation phase transition in magnets has been investigated in an external magnetic field. The influence of an external field and one-dimensional defects of magnetic anisotropy on the dynamics of such nucleus has been demonstrated. The conditions for the localization of the new-phase nucleus in the region of the magnetic anisotropy defect and for its escape from the defect have been determined. The values of the critical fields which bring about the sample magnetization reversal have been identified and estimated.

scholarly journals Magnetic-field induced quantum phase transition and critical behavior in a gapped spin system

2007 ◽  
Vol 310 (2) ◽  
pp. 1352-1354 ◽  
Author(s):  
F. Yamada ◽  
T. Ono ◽  
M. Fujisawa ◽  
H. Tanaka ◽  
T. Sakakibara
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Quantum Phase Transition ◽  
Spin System ◽  
Critical Behavior ◽  
Quantum Phase

Effect of high magnetic field on the two-step martensitic-phase transition in Ni2MnGa

2000 ◽  
Vol 76 (1) ◽  
pp. 37-39 ◽  
Author(s):  
Yanwei Ma ◽  
S. Awaji ◽  
K. Watanabe ◽  
M. Matsumoto ◽  
N. Kobayashi
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
High Magnetic Field ◽  
Martensitic Phase ◽  
Martensitic Phase Transition

A NONPERTURBATIVE CALCULATION FOR THE EFFECTIVE POTENTIAL OF THE $\left(\frac{g}{4}\phi^{4}-J\phi\right)_{1+1}$ SCALAR FIELD THEORY USING THE OSCILLATOR REPRESENTATION METHOD WITH BOREL RESUMMATION

2007 ◽  
Vol 22 (06) ◽  
pp. 1265-1278
Author(s):  
ABOUZEID M. SHALABY ◽  
S. T. EL-BASYOUNY
Keyword(s):  
Magnetic Field ◽  
Field Theory ◽  
Phase Transition ◽  
Scalar Field ◽  
External Magnetic Field ◽  
Effective Potential ◽  
Oscillator Representation ◽  
Constructive Field Theory ◽  
Representation Method ◽  
Oscillator Representation Method

We established a resummed formula for the effective potential of [Formula: see text] scalar field theory that can mimic the true effective potential not only at the critical region but also at any point in the coupling space. We first extend the effective potential from the oscillator representation method, perturbatively, up to g3 order. We supplement perturbations by the use of a resummation algorithm, originally due to Kleinert, Thoms and Janke, which has the privilege of using the strong coupling as well as the large coupling behaviors rather than the conventional resummation techniques which use only the large order behavior. Accordingly, although the perturbation series available is up to g3 order, we found a good agreement between our resummed effective potential and the well-known features from constructive field theory. The resummed effective potential agrees well with the constructive field theory results concerning existing and order of phase transition in the absence of an external magnetic field. In the presence of the external magnetic field, as in magnetic systems, the effective potential shows nonexistence of phase transition and gives the behavior of the vacuum condensate as a monotonic increasing function of J, in complete agreement with constructive field theory methods.

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