CMSP Series @ICTP Stasi Room Thursday 9 August 11:30 am - O. ROJAS SANTOS

[CM Section]

ICTP Seminar Series in Condensed Matter and Statistical Physics
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Thursday 9 August at 11:30 a.m.- KINDLY note TIME

Luigi Stasi Seminar Room, first floor, ICTP Leonardo building
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Speaker: Onofre ROJAS SANTOS

Title: Further Evidence for Quasi-Phases and Pseudo-Transitions in
One-Dimensional Models

Abstract:
One-dimensional systems with short-range interactions cannot exhibit a
long-range order at nonzero temperature. However, there are some particular
one-dimensional models, such as the Ising-Heisenberg spin models with a
variety of lattice geometries, which exhibit unexpected behavior similar 
to the
discontinuous or continuous temperature-driven phase transition. 
Although these
pseudo-transitions are not true temperature-driven transitions showing 
only abrupt
changes or sharp peaks in thermodynamic quantities, they may be confused 
while
interpreting experimental data. Here we consider the spin-\frac{1}{2} 
Ising-XYZ diamond
chain in the regime when the model exhibits temperature-driven 
pseudo-transitions.
We provide a detailed investigation of how this phenomenon occurs in 
several physical
quantities, such as entropy, magnetization, specific heat, magnetic 
susceptibily, and
correlation functions between distant spins that illustrates the 
properties of quasi-phases
separated by pseudo-transitions. Inevitably, all correlation functions 
show the evidence
of pseudo-transition. It is worth to mention that the correlation 
functions between distant
spins have an extremely large correlation length at pseudo-critical 
temperature.