Sm valence and closure of the correlation gap in the Kondo insulator SmB6

The aim of the present proposal is to probe Sm Valence and magnetic state across the magnetic field induced closure of the correlation gap. In resistivity measurements, the closure has been observed at 89 T. It has also been shown, that the correlation gap inferred from resistivity measurements can be reduced through through the application of pressure at a rate of -0.7meV/GPa. We therefore use pressure to reduce and tune the gap, and pulsed high magnetic fields up to 30T in order to reach the expected closure. Previous measurements at ambient pressure and pressures up to 1.9 GPa did not show a significant evolution of the Sm valence contrary to expectations. In this continuation we therefore aim to corroborate this observation and to extend our measurements to higher pressures.

本研究提案旨在探究磁场诱导关联能隙闭合过程中钐（Sm）的价态与磁状态。在电阻率测量中，该能隙闭合现象已于89特斯拉（T）的磁场下被观测到。另有研究表明，通过施加压力，由电阻率测量推导得到的关联能隙可被调控，其变化速率为-0.7毫电子伏特每吉帕斯卡（meV/GPa）。因此本研究将通过施加压力来调控并缩小该能隙，并结合最高场强达30特斯拉（T）的脉冲强磁场，以实现预期的能隙闭合。此前在常压以及最高1.9吉帕斯卡（GPa）压力下开展的测量结果显示，钐价态并未如预期般发生显著变化。在本次延续性研究中，我们旨在验证该观测结果，并将测量范围拓展至更高压力区间。