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arXiv · 1610.02222

Current-induced giant diamagnetism in the Mott insulator Ca2RuO4

Chanchal Sow·Shingo Yonezawa·Sota Kitamura·Takashi Oka·Kazuhiko Kuroki·Fumihiko Nakamura·Yoshiteru Maeno
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Abstract

Mott insulators have surprised us many times by hosting new and diverse quantum phenomena when the frozen electrons are perturbed by various stimuli. Superconductivity, metal-insulator transition, and colossal magnetoresistance induced by element substitution, pressure, and magnetic field are prominent examples. Here we report a novel phenomenon, namely giant diamagnetism, in the Mott insulator Ca2RuO4 induced by electric current. With application of 1 A/cm2 current, the strongest diamagnetism among all nonsuperconducting materials is induced as the system is tuned to a semimetallic state. The origin lies in the emergence of indirect Dirac cones in the many-body spectrum and associated monopole-like anomaly in the momentum dependent susceptibility. This record-breaking and switchable diamagnetism is a new class of non-equilibrium quantum phenomena on the verge of Mott insulating states.

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Chanchal Sow, Shingo Yonezawa, Sota Kitamura, Takashi Oka, Kazuhiko Kuroki, Fumihiko Nakamura, Yoshiteru Maeno. 2016-10-07. Current-induced giant diamagnetism in the Mott insulator Ca2RuO4. https://doi.org/10.1126/science.aah4297

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