Ultra-fast photo-carrier relaxation in Mott insulators with short-range spin correlations

AbstractInvestigations of magnetically ordered phases on the femtosecond timescale have provided significant insights into the influence of charge and lattice degrees of freedom on the magnetic sub-system. However, short-range magnetic correlations occurring in the absence of long-range order, for example in spin-frustrated systems, are inaccessible to many ultrafast techniques. Here, we show how time-resolved resonant inelastic X-ray scattering (trRIXS) is capable of probing such short-ranged magnetic dynamics in a charge-transfer insulator through the detection of a Zhang–Rice singlet exciton. Utilizing trRIXS measurements at the O K-edge, and in combination with model calculations, we probe the short-range spin correlations in the frustrated spin chain material CuGeO3 following photo-excitation, revealing a strong coupling between the local lattice and spin sub-systems.

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Itinerancy effects on spin correlations in one-dimensional Mott insulators

Physical Review B ◽

10.1103/physrevb.71.020405 ◽

2005 ◽

Vol 71 (2) ◽

Cited By ~ 10

Author(s):

M. J. Bhaseen ◽

F. H. L. Essler ◽

A. Grage

Keyword(s):

Mott Insulators ◽

Spin Correlations ◽

One Dimensional

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Short-range Berezinskii-Kosterlitz-Thouless Phase Characterization for the q-state Clock Model

10.20944/preprints202107.0291.v1 ◽

2021 ◽

Author(s):

Oscar Andres Negrete ◽

Patricio Vargas ◽

Francisco Jose Peña ◽

Gonzalo Saravia ◽

Eugenio Emilio Vogel

Keyword(s):

Short Range ◽

Nearest Neighbors ◽

Vortex State ◽

Spin Systems ◽

Xy Model ◽

Clock Model ◽

Spin Correlations ◽

Vortex States ◽

Higher Temperature ◽

Phase Characterization

Beyond the usual ferromagnetic and paramagnetic phases present in spin systems, the usual q-state clock model, presents an intermediate vortex state when the number of possible orientations q for the system is equal to 5 or larger. Such vortex states give rise to the Berezinskii-Kosterlitz-Thouless (BKT) phase present up to the XY model in the limit q→∞. Based on information theory, we present here an analysis of the classical order parameters plus new short-range parameters defined here. Thus, we show that even using the first nearest neighbors spin-spin correlations only, it is possible to distinguish the two transitions presented by this system for q greater than or equal to 5. Moreover, the appearance at relatively low temperature and disappearance of the BKT phase at a rather fix higher temperature is univocally determined by the short-range interactions recognized by the information content of classical and new parameters.

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