INVESTIGADORES
ROSSINI Gerardo Luis
artículos
Título:
QUANTUM PHASES OF A FRUSTRATED FOUR-LEG SPIN TUBE
Autor/es:
MARCELO ARLEGO; WOLFRAM BRENIG; RAHNAVARD, Y.; WILLENBERG, B.; ROSALES, HÉCTOR; GERARDO ROSSINI
Revista:
PHYSICAL REVIEW B
Editorial:
AMER PHYSICAL SOC
Referencias:
Lugar: New York; Año: 2013 vol. 87 p. 14412 - 14421
ISSN:
1098-0121
Resumen:
We study the ground-state phase diagram of a frustrated spin-1/2 four-leg tube. Using a variety of
complementary techniques, namely, density matrix renormalization group, exact diagonalization, Schwinger
boson mean-field theory, quantum Monte Carlo, and series expansion, we explore the parameter space of this
model in the regime of all-antiferromagnetic exchange. In contrast to unfrustrated four-leg tubes, we uncover a
rich phase diagram. Apart from the Luttinger liquid fixed point in the limit of decoupled legs, this comprises
several gapped ground states, namely, a plaquette, an incommensurate, and an antiferromagnetic quasispin-2
chain phase. The transitions between these phases are analyzed in terms of total energy and static structure factor
calculations and are found to be of (weak) first order. Despite the absence of long-range order in the quantum case,
remarkable similarities to the classical phase diagram are uncovered, with the exception of the icommensurate
regime, which is strongly renormalized by quantum fluctuations. In the limit of large leg exchange, the tube
exhibits a deconfinement crossover from gapped magnon-like excitations to spinons.