2013/09/04 by Ryuji Okazaki, R. Okazaki, Yasuo Nishina +9
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Electronic and Structural Properties of Oxides #Infrared #Insulator (electricity) #Joule heating #Metal–insulator transition #Mott insulator #Nonlinear system #Physics of Superconductivity and Magnetism #Superconductivity #Thermal conduction #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.7566/jpsj.82.103702
published as J. Phys. Soc. Jpn. 82, 103702 (2013) · 5 pages, 3 figures, to be published in J. Phys. Soc. Jpn
arxiv created 2013/09/04 · arxiv updated 2013/09/05 · openalex publication_date 2013/09/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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.