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arXiv · 1111.5666

Beyond the quantum spin liquid concept in frustrated two dimensional organic superconductors

R. T. Clay·S. Dayal·H. Li·S. Mazumdar
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Abstract

The occurrence of antiferromagnetism in kappa-(ET)_2X can be understood within an effective 1/2-filled band with dimers of ET molecules containing one hole each. We argue that while this effective model can describe the presence of antiferromagnetism, a complete description for these materials requires the correct carrier density of one-half per molecule. For dimerized and strongly frustrated 1/4-filled lattices we show that a singlet-paired state coexisting with charge ordering occurs that we have termed the Paired Electron Crystal (PEC). Here we investigate the 1/4-filled model on a dimerized lattice, showing regions where AFM, PEC, and the Wigner-crystal occur. We point out the need to go beyond quantum spin liquid concepts for highly frustrated materials such as kappa-(ET)_2Cu_2(CN)_3 and beta'-EtMe_3Sb[Pd(dmit)_2]_2 which we believe are PECs at low temperatures.

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R. T. Clay, S. Dayal, H. Li, S. Mazumdar. 2011-11-24. Beyond the quantum spin liquid concept in frustrated two dimensional organic superconductors. https://doi.org/10.1002/pssb.201100727

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