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تسجيل مستخدم جديدCurrent-Induced Gap Suppression in the Mott Insulator Ca$_2$RuO$_4$
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We present nonlinear conduction phenomena in the Mott insulator Ca2RuO4 investigated with a proper evaluation of self-heating effects. By utilizing a non-contact infrared thermometer, the sample temperature was accurately determined even in the presence of large Joule heating. We find that the resistivity continuously decreases with currents under an isothermal environment. The nonlinearity and the resulting negative differential resistance occurs at relatively low current range, incompatible with conventional mechanisms such as hot electron or impact ionization. We propose a possible current-induced gap suppression scenario, which is also discussed in non-equilibrium superconducting state or charge-ordered insulator.
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A paradigmatic case of multi-band Mott physics including spin-orbit and Hunds coupling is realised in Ca$_2$RuO$_4$. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy ele
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