Tuning the superconducting transition of SrTiO3-based 2DEGs with light
Tuning the superconducting transition of SrTiO3-based 2DEGs with light
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DOI：
10.1063/1.5119417
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发表时间：
2019-09-16
影响因子：
4
通讯作者：
Schaefer, P.
中科院分区：
文献类型：
--
作者：
Arnold, D.;Fuchs, D.;Schaefer, P.
在钛酸锶与各种氧化物的界面处形成的二维电子气的电阻率对来自可见光的照射敏感。在这封信中，我们提出的数据之间的带隙绝缘体LaAlO 3（LAO）和SrTiO 3（STO）的界面。我们在低于1 K的温度下操作发光二极管，并利用它在超低温下照射LAO/STO界面。在辐照时，该系统的电阻连续降低五倍，并且只要样品保持在黑暗中，电阻变化在低温下就持续存在。这使得在延长的时间段内在不同的电阻状态下的传输特性的表征成为可能。我们的原始样本温度低于265 mK。转变温度T-c向下移动的持续光诱导的电阻降低。当温度高于10 K时，持续光电导可完全恢复，此时Tc恢复到原来的值。因此，非常类似于场效应引起的电子密度的变化，在低温下的照射为基于STO的界面的超导状态提供了一个通用的调谐旋钮，其另外具有非易失性的优点。
The resistivity of the two dimensional electron gas that forms at the interface of strontium titanate with various oxides is sensitive to irradiation from visible light. In this letter, we present data on the interface between the bandgap insulators LaAlO3 (LAO) and SrTiO3 (STO). We operate a light emitting diode at temperatures below 1 K and utilize it to irradiate the LAO/STO interface at ultralow temperatures. On irradiation, the resistance of this system is lowered continuously by a factor of five and the resistance change is persistent at low temperatures as long as the sample is kept in the dark. This makes the characterization of transport properties in different resistive states over extended time periods possible. Our pristine sample gets superconductive below 265 mK. The transition temperature T-c shifts downward on the persistent photo-induced lowering of the resistance. The persistent photoconductance can be completely reverted by heating the structure above 10 K, in which case, T-c takes on its original value. Thus, very similar to field-effect induced changes of the electron density, irradiation at low temperatures offers a versatile tuning knob for the superconducting state of STO-based interfaces which in addition has the advantage to be nonvolatile.