QUANTUM GLASSINESS AND SUPERCONDUCTIVITY IN DOPED LOW DIMENSIONAL ANTIFERROMAGNETS

2008 ◽  
Vol 22 (16) ◽  
pp. 2501-2516 ◽  
Author(s):  
CHRISTOS PANAGOPOULOS
Keyword(s):  
Phase Transition ◽  
Critical Point ◽  
Direct Observation ◽  
Ground State ◽  
Glassy State ◽  
Quantum Critical Point ◽  
Intrinsic Property ◽  
Material Quality ◽  
Abrupt Changes ◽  
Low Dimensional

Following the direct observation of abrupt changes in the superconducting ground state in doped low dimensional antiferromagnets, we have identified a phase transition where superconductivity is optimal. The experiments indicate the presence of a putative quantum critical point associated with the emergence of a glassy state. This mechanism is argued to be an intrinsic property and as such, largely independent of material quality and the level of disorder.

scholarly journals Variational procedure leading from Davidson potentials to the E(5)and X(5) critical point symmetries

2020 ◽  
Vol 13 ◽  
pp. 10
Author(s):  
Dennis Bonatsos ◽  
D. Lenis ◽  
N. Minkov ◽  
D. Petrellis ◽  
P. P. Raychev ◽  
...  
Keyword(s):  
Phase Transition ◽  
Critical Point ◽  
Ground State ◽  
Nuclear Energy ◽  
Energy Spectra ◽  
Variational Procedure ◽  
Ground State Band ◽  
Sharp Maximum ◽  
State Band ◽  
Shape Phase Transition

Davidson potentials of the form β^2 + β0^4/β^2, when used in the original Bohr Hamiltonian for γ-independent potentials bridge the U(5) and 0(6) symmetries. Using a variational procedure, we determine for each value of angular momentum L the value of β0 at which the derivative of the energy ratio RL = E(L)/E(2) with respect to β0 has a sharp maximum, the collection of RL values at these points forming a band which practically coincides with the ground state band of the E(5) model, corresponding to the critical point in the shape phase transition from U(5) to Ο(6). The same potentials, when used in the Bohr Hamiltonian after separating variables as in the X(5) model, bridge the U(5) and SU(3) symmetries, the same variational procedure leading to a band which practically coincides with the ground state band of the X(5) model, corresponding to the critical point of the U(5) to SU(3) shape phase transition. A new derivation of the Holmberg-Lipas formula for nuclear energy spectra is obtained as a by-product.

scholarly journals Direct Observation of the Quantum Critical Point in Heavy FermionCeRhSi3

2012 ◽  
Vol 108 (17) ◽  
Author(s):  
N. Egetenmeyer ◽  
J. L. Gavilano ◽  
A. Maisuradze ◽  
S. Gerber ◽  
D. E. MacLaughlin ◽  
...  
Keyword(s):  
Critical Point ◽  
Direct Observation ◽  
Quantum Critical Point ◽  
Quantum Critical

scholarly journals Avoided ferromagnetic quantum critical point: Antiferromagnetic ground state in substituted CeFePO

2016 ◽  
Vol 254 (1) ◽  
pp. 1600169 ◽  
Author(s):  
A. Jesche ◽  
T. Ballé ◽  
K. Kliemt ◽  
C. Geibel ◽  
M. Brando ◽  
...  
Keyword(s):  
Critical Point ◽  
Ground State ◽  
Quantum Critical Point ◽  
Antiferromagnetic Ground State ◽  
Quantum Critical

scholarly journals The emergence of strange metal and topological liquid near quantum critical point in a solvable model

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Eunseok Oh ◽  
Taewon Yuk ◽  
Sang-Jin Sin
Keyword(s):  
Phase Transition ◽  
Phase Diagram ◽  
Critical Point ◽  
Zero Mode ◽  
Quantum Critical Point ◽  
Solvable Model ◽  
Phase Boundaries ◽  
Metal To Insulator Transition ◽  
Quantum Critical ◽  
Fermion Zero Mode

Abstract We discuss quantum phase transition by a solvable model in the dual gravity setup. By considering the effect of the scalar condensation on the fermion spectrum near the quantum critical point(QCP), we find that there is a topologically protected fermion zero mode associated with the metal to insulator transition. Unlike the topological insulator, our zero mode is for the bulk of the material, not the edge. We also show that the strange metal phase with T-linear resistivity emerges at high enough temperature as far as a horizon exists. The phase boundaries calculated according to the density of states allow us understanding the structures of the phase diagram near the QCP.

scholarly journals Entropies and IPR as Markers for a Phase Transition in a Two-Level Model for Atom–Diatomic Molecule Coexistence

Entropy ◽  
2022 ◽  
Vol 24 (1) ◽  
pp. 113
Author(s):  
Ignacio Baena ◽  
Pedro Pérez-Fernández ◽  
Manuela Rodríguez-Gallardo ◽  
José Miguel Arias
Keyword(s):  
Phase Transition ◽  
Ground State ◽  
Large Particle ◽  
State Energy ◽  
Particle Number ◽  
Diatomic Molecules ◽  
The Other ◽  
Abrupt Changes ◽  
Level Model ◽  
Two Level Model

A quantum phase transition (QPT) in a simple model that describes the coexistence of atoms and diatomic molecules is studied. The model, which is briefly discussed, presents a second-order ground state phase transition in the thermodynamic (or large particle number) limit, changing from a molecular condensate in one phase to an equilibrium of diatomic molecules–atoms in coexistence in the other one. The usual markers for this phase transition are the ground state energy and the expected value of the number of atoms (alternatively, the number of molecules) in the ground state. In this work, other markers for the QPT, such as the inverse participation ratio (IPR), and particularly, the Rényi entropy, are analyzed and proposed as QPT markers. Both magnitudes present abrupt changes at the critical point of the QPT.

scholarly journals Novel Phase Transition Near the Quantum Critical Point in the Filled-Skutterudite Compound CeOs4Sb12: An Sb-NQR Study

2005 ◽  
Vol 74 (7) ◽  
pp. 1950-1953 ◽  
Author(s):  
Mamoru Yogi ◽  
Hisashi Kotegawa ◽  
Guo-qing Zheng ◽  
Yoshio Kitaoka ◽  
Shuji Ohsaki ◽  
...  
Keyword(s):  
Phase Transition ◽  
Critical Point ◽  
Quantum Critical Point ◽  
Filled Skutterudite ◽  
Quantum Critical ◽  
Skutterudite Compound
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