scholarly journals Influence of a magnetic field on the two-dimensional phase transition in thin-film superconductors

1987 ◽  
Vol 36 (7) ◽  
pp. 3638-3650 ◽  
Author(s):  
J. C. Garland ◽  
Hu Jong Lee
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Phase Transition ◽  
Two Dimensional

MAGNETORESISTIVITY PROPERTIES AND EFFECTIVE ACTIVATION ENERGY IN YBa2Cu3O7-ρ SUPERCONDUCTING THIN FILM

2006 ◽  
Vol 20 (29) ◽  
pp. 1847-1852
Author(s):  
ALI IHSAN DEMIREL ◽  
SALIM ORAK
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Activation Energy ◽  
Applied Field ◽  
Effective Activation Energy ◽  
Creep Process ◽  
Two Dimensional ◽  
Effective Activation ◽  
Exponential Behavior ◽  
Superconducting Thin Film

The resistive properties and activation energy of YBa 2 Cu 3 O 7-ρ ( YBCO ) superconducting materials change in magnetic field. It is explained that magnetoresistive behavior in terms of the presence of two-dimensional vortices being pinned effectively when they are perpendicular to the CuO 2 planes and an exponential behavior of the activation energy versus the applied field was obtained. The resulting activation energies ranging from 1 to 5 Tesla were attributed to inter-granular flux creep process.

scholarly journals Magnetic Field and Phase Transition in Thin Film Superconductors

1963 ◽  
Vol 11 (3) ◽  
pp. 119-121 ◽  
Author(s):  
Yoichiro Nambu ◽  
San Fu Tuan
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Phase Transition

scholarly journals MODELING THIN CURVED FERROMAGNETIC FILMS

2005 ◽  
Vol 03 (04) ◽  
pp. 373-396
Author(s):  
HAMDI ZORGATI
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Free Energy ◽  
Ferromagnetic Material ◽  
Local Energy ◽  
Two Dimensional ◽  
Energy Term ◽  
Anisotropic Energy ◽  
Saturation Constraint ◽  
Γ Convergence

The behavior of a thin film made of a ferromagnetic material in the absence of an external magnetic field is described by an energy depending on the magnetization of the film verifying the saturation constraint. The free energy consists of an induced magnetostatic energy and an energy term with density including the exchange energy and the anisotropic energy. We study the behavior of this energy when the thickness of the curved film goes to zero. We show that the minimizers of the free energy converge to the minimizers of a local energy depending on a two-dimensional magnetization by Γ-convergence arguments.

Phase Transition in 2D Anisotropic Ising Model with Next-Nearest Neighbor Interactions in a Magnetic Field

SPIN ◽  
2018 ◽  
Vol 08 (03) ◽  
pp. 1850010
Author(s):  
D. Farsal ◽  
M. Badia ◽  
M. Bennai
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Phase Diagram ◽  
Monte Carlo ◽  
Magnetic Susceptibility ◽  
Critical Temperature ◽  
Ising Model ◽  
Nearest Neighbor ◽  
Two Dimensional ◽  
The Magnetic Field

The critical behavior at the phase transition of the ferromagnetic two-dimensional anisotropic Ising model with next-nearest neighbor (NNN) couplings in the presence of the field is determined using mainly Monte Carlo (MC) method. This method is used to investigate the phase diagram of the model and to verify the existence of a divergence at null temperature which often appears in two-dimensional systems. We analyze also the influence of the report of the NNN interactions [Formula: see text] and the magnetic field [Formula: see text] on the critical temperature of the system, and we show that the critical temperature depends on the magnetic field for positive values of the interaction. Finally, we have investigated other thermodynamical qualities such as the magnetic susceptibility [Formula: see text]. It has been shown that their thermal behavior depends qualitatively and quantitatively on the strength of NNN interactions and the magnetic field.

scholarly journals Hybridization and Field Driven Phase Transitions in Hexagonally Warped Topological Insulators

SPIN ◽  
2016 ◽  
Vol 06 (02) ◽  
pp. 1640005 ◽  
Author(s):  
Anirudha Menon ◽  
Debashree Chowdhury ◽  
Banasri Basu
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Phase Transition ◽  
Phase Transitions ◽  
Electric Field ◽  
Surface States ◽  
Material Parameters ◽  
Insulator Phase Transition ◽  
Tilted Magnetic Field

In this paper, we discuss the role of material parameters and external field effects on a thin film topological insulator(TI) in the context of quantum phase transition (QPT). First, we consider an in-plane tilted magnetic field and determine the band structure of the surface states as a function of the tilt angle. We show that the presence of either a hybridization term or hexagonal warping or a combination of both leads to a semi-metal to insulator phase transition which is facilitated by their [Formula: see text] symmetry breaking character. We then note that while the introduction of an electric field does not allow for this QPT since it does not break [Formula: see text] symmetry, it can be used in conjunction with a tunneling element to reach a phase transition efficiently. The corresponding critical point is then nontrivially dependent on the electric field, which is pointed out here. Then, we demonstrate that including a hexagonal warping term leads to an immediate [Formula: see text] symmetry violating QPT.

LOCAL MINIMIZERS FOR THE GINZBURG–LANDAU ENERGY NEAR CRITICAL MAGNETIC FIELD: PART I

1999 ◽  
Vol 01 (02) ◽  
pp. 213-254 ◽  
Author(s):  
SYLVIA SERFATY
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Critical Value ◽  
Critical Magnetic Field ◽  
Two Dimensional ◽  
Local Minimizers ◽  
Large Parameter ◽  
Ginzburg Landau

We find local minimizers of the two-dimensional Ginzburg–Landau functionals depending on a large parameter κ, which describe the behavior of a superconductor in a prescribed exterior magnetic field hex. We prove an estimate on the critical value Hc1 of hex(κ), corresponding to the first phase-transition in which vortices appear in the superconductor; and we locate these vortices.

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