Juyal Abhishek, Agarwal Amit, Mukhopadhyay Soumik
Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Phys Rev Lett. 2018 Mar 2;120(9):096801. doi: 10.1103/PhysRevLett.120.096801.
The ground state of nanowires of single-crystalline pyrochlore Y_{2}Ir_{2}O_{7} is a density wave. The application of a transverse magnetic field increases the threshold electric field for the collective depinning of the density wave state at a low temperature, leading to colossal magnetoresistance for voltages around the depinning threshold. This is in striking contrast to the case where even a vanishingly small longitudinal magnetic field sharply reduces the depinning threshold voltage, resulting in negative magnetoresistance. Ruling out several other possibilities, we argue that this phenomenon is likely to be a consequence of the chiral anomaly in the gapped out Weyl semimetal phase in Y_{2}Ir_{2}O_{7}.
单晶焦绿石Y₂Ir₂O₇纳米线的基态是一种密度波。施加横向磁场会提高低温下密度波态集体脱钉的阈值电场，导致在脱钉阈值附近的电压出现巨大磁阻。这与即使是极小的纵向磁场也会急剧降低脱钉阈值电压从而导致负磁阻的情况形成鲜明对比。排除其他几种可能性后，我们认为这种现象很可能是Y₂Ir₂O₇中带隙外尔半金属相的手征反常的结果。
