scholarly journals Finite-temperature phase transition in ϕ6 potential

2008 ◽  
Vol 86 (11) ◽  
pp. 1313-1319 ◽  
Author(s):  
H Widyan
Keyword(s):  
Phase Transition ◽  
Low Temperatures ◽  
Scalar Potential ◽  
Thick Wall ◽  
Temperature Phase ◽  
Thin Wall ◽  
Quantum Tunnelling ◽  
First Order ◽  
Temperature Phase Transition ◽  
Temperature Dependance

The temperature dependance of the action in thin-wall and thick-wall limits is obtained analytically for the ϕ6 scalar potential. The nature of the phase transition is investigated from the quantum tunnelling regime at low temperatures to the thermal hopping regime at high temperatures. It is first-order for the case of a thin wall while for the thick wall it is second- order. PACS Nos.: 10.10.Wx, 05.70.Fh, 10.10.Ef

QUANTUM TUNNELLING OR THERMAL HOPPING

2000 ◽  
Vol 14 (19n20) ◽  
pp. 2109-2116
Author(s):  
N. PANCHAPAKESAN
Keyword(s):  
Quantum Tunneling ◽  
Condensed Matter ◽  
Order Term ◽  
Thick Wall ◽  
Thin Wall ◽  
Quantum Tunnelling ◽  
First Order ◽  
Classical State ◽  
Fourth Order Term ◽  
Loss Of Coherence

The nature of the transition from the quantum tunneling regime to the thermal hopping regime has importance in the study of condensed matter physics and cosmological phase transitions. It may also be of significance in collapse from quantum state to a classical state due to measurement (or loss of coherence due to some other process). We study this transition analytically in scalar field theory with a fourth order term. We obtain analytic bounce solutions which correctly give the action in thin and thick wall limits of the potential. We find that the transition is of the second order for the case of thick wall while it seems to be of first order for the case of thin wall.

scholarly journals Components Influence On Dielectric Properties Of Ferroelectric Composite Materials

2016 ◽  
Vol 1 (1) ◽  
pp. 51
Author(s):  
O.V. Efimova ◽  
E.V. Stukova ◽  
E.Yu. Koroleva
Keyword(s):  
Phase Transition ◽  
Dielectric Properties ◽  
Ferroelectric Phase ◽  
Volume Fraction ◽  
Temperature Phase ◽  
Cooling Mode ◽  
First Order ◽  
First Order Phase Transition ◽  
Temperature Phase Transition ◽  
First Order Phase

<p>The dielectric properties of ferroelectric composite (NH<sub>4</sub>HSO<sub>4</sub>)<em><sub>x</sub></em>/(PbTiO<sub>3</sub>)<em><sub>1-x</sub></em> is studied for x ranging from 0,00 to 0,50. Measurements of permittivity were performed by heating-cooling mode temperature range from 130 K to 380 K. The value of the temperature interval of existence of the ferroelectric phase increases by ~5 degrees and independent at the volume fraction of particulate inclusions in composites. It is shown that the inclusion of PbTiO<sub>3</sub> particles gives rise to hysteresis upper temperature phase transition, which may indicate a change in the type of phase transition of the second order on the first-order phase transition.</p>

scholarly journals FINITE TEMPERATURE PHASE TRANSITION OF A SCALAR FIELD ON A FUZZY SPHERE

2008 ◽  
Vol 23 (21) ◽  
pp. 1781-1791 ◽  
Author(s):  
C. R. DAS ◽  
S. DIGAL ◽  
T. R. GOVINDARAJAN
Keyword(s):  
Phase Transition ◽  
Scalar Field ◽  
Finite Temperature ◽  
Zero Mode ◽  
Temperature Phase ◽  
Fuzzy Sphere ◽  
Stable States ◽  
First Order ◽  
Auto Correlation ◽  
Temperature Phase Transition

We study finite temperature phase transition of neutral scalar field on a fuzzy sphere using Monte Carlo simulations. We work with the zero mode in the temporal directions, while the effects of the higher modes are taken care by the temperature dependence of r. In the numerical calculations we use "pseudo-heatbath" method which reduces the auto-correlation considerably. Our results agree with the conventional calculations. We report some new results which show the presence of meta-stable states, first order symmetry breaking transition and existence of multiple triple points in the phase diagram..

THE SPECTRUM OF THE $\mathcal{T}$-MATRIX AND THE SURFACE TENSION IN THE SU(3) GAUGE THEORY

1992 ◽  
Vol 03 (05) ◽  
pp. 947-960 ◽  
Author(s):  
T. TRAPPENBERG
Keyword(s):  
Phase Transition ◽  
Surface Tension ◽  
Gauge Theory ◽  
Finite Size ◽  
Temperature Phase ◽  
Finite Size Effects ◽  
First Order ◽  
First Order Phase Transition ◽  
Temperature Phase Transition ◽  
First Order Phase

The transfer matrix method to describe finite size effects due to tunneling are worked out for Z(2)- and Z(3)-symmetric models. We used this method to extract the surface tension σ in the SU(3) gauge theory at the finite temperature phase transition on lattices with an extent T=2 in the euclidean time direction. We also discuss if the confined phase completely wets the deconfined phase at this first order phase transition.

scholarly journals Chiral Transition of SU(4) Gauge Theory with Fermions in Multiple Representations

2018 ◽  
Vol 175 ◽  
pp. 08026 ◽  
Author(s):  
Venkitesh Ayyar ◽  
Thomas DeGrand ◽  
Daniel C. Hackett ◽  
William I. Jay ◽  
Ethan T. Neil ◽  
...  
Keyword(s):  
Phase Transition ◽  
Stability Analysis ◽  
Gauge Theory ◽  
Finite Temperature ◽  
Temperature Phase ◽  
Scale Separation ◽  
First Order ◽  
Chiral Transition ◽  
Temperature Phase Transition ◽  
Separation Behavior

We report preliminary results on the finite temperature behavior of SU(4) gauge theory with dynamical quarks in both the fundamental and two-index antisymmetric representations. This system is a candidate to present scale separation behavior, where fermions in different representations condense at different temperature or coupling scales. Our simulations, however, reveal a single finite-temperature phase transition at which both representations deconfine and exhibit chiral restoration. It appears to be strongly first order. We compare our results to previous single-representation simulations. We also describe a Pisarski-Wilczek stability analysis, which suggests that the transition should be first order.

scholarly journals Fate of false vacua in holographic first-order phase transitions

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Francesco Bigazzi ◽  
Alessio Caddeo ◽  
Aldo L. Cotrone ◽  
Angel Paredes
Keyword(s):  
Phase Transitions ◽  
Chiral Symmetry ◽  
Metastable Phase ◽  
Chiral Symmetry Breaking ◽  
Model Parameters ◽  
Temperature Phase ◽  
Thin Wall ◽  
Critical Temperatures ◽  
First Order ◽  
First Order Phase

Abstract Using the holographic correspondence as a tool, we study the dynamics of first-order phase transitions in strongly coupled gauge theories at finite temperature. Considering an evolution from the large to the small temperature phase, we compute the nucleation rate of bubbles of true vacuum in the metastable phase. For this purpose, we find the relevant configurations (bounces) interpolating between the vacua and we compute the related effective actions. We start by revisiting the compact Randall-Sundrum model at high temperature. Using holographic renormalization, we compute the derivative term in the effective bounce action, that was missing in the literature. Then, we address the full problem within the top-down Witten-Sakai-Sugimoto model. It displays both a confinement/deconfinement and a chiral symmetry breaking/restoration phase transition which, depending on the model parameters, can happen at different critical temperatures. For the confinement/deconfinement case we perform the numerical analysis of an effective description of the transition and also provide analytic expressions using thick and thin wall approximations. For the chiral symmetry transition, we implement a variational approach that allows us to address the challenging non-linear problem stemming from the Dirac-Born-Infeld action.

scholarly journals High-temperature phase transition of SrRuO3and SrHfO5: X-ray diffraction and PAC spectroscopy

1996 ◽  
Vol 52 (a1) ◽  
pp. C364-C364
Author(s):  
J. A. Guevara ◽  
S. L. Cuffini ◽  
Y. P. Mascarenhas ◽  
P. de la Presa ◽  
A. Ayala ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Pac Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Phase Transition
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