通过离子液体选择性调控铜氧化物中的易失和非易失超导电性

A selective control of volatile and non-volatile superconductivity in an insulating copper oxide via ionic liquid gating

高效、可靠地调控铜氧化物超导体的超导态,对其在下一代电子学中的应用具有重要意义.本文研究了绝缘Pr2CuO4±δ(PCO)薄膜的离子液体调控行为,发现可以利用两种不同的调控机制分别诱导出易失和非易失的超导态.在正电场调控下,薄膜可以在超导态和非超导态之间可逆转换,这归因于载流子的掺杂效应.另外,对绝缘的样品进行负偏压的调控,当偏压加至-4 V时,样品的电阻明显增大.值得关注的是,一旦撤去栅极电压,样品获得了非易失的超导电性.高分辨扫描电子显微镜和原位X射线衍射实验的结果表明,负向调控过程修复了铜氧面中的氧空位.对于电子型铜氧化物而言,这是一种诱导超导电性的独特途径.在同一个铜氧化物母体中有效地调控易失和非易失超导电性,为超导电子器件和高温超导体中量子相变的研究提供了新的渠道.

Manipulating the superconducting states of high transition temperature(high-Tc)cuprate superconductors in an efficient and reliable way is of great importance for their applications in next-generation electronics.Here,employing ionic liquid gating,a selective control of volatile and non-volatile superconductivity is achieved in pristine insulating Pr2CuO4±δ(PCO)films,based on two distinct mechanisms.Firstly,with positive electric fields,the film can be reversibly switched between superconducting and non-superconducting states,attributed to the carrier doping effect.Secondly,the film becomes more resistive by applying negative bias voltage up to-4V,but strikingly,a non-volatile superconductivity is achieved once the gate voltage is removed.Such phenomenon represents a distinctive route of manipulating superconductivity in PCO,resulting from the doping healing of oxygen vacancies in copper-oxygen planes as unravelled by high-resolution scanning transmission electron microscope and in situ X-ray diffraction experiments.The effective manipulation of volatile/non-volatile superconductivity in the same parent cuprate brings more functionalities to superconducting electronics,as well as supplies flexible samples for investigating the nature of quantum phase transitions in high-Tcsuperconductors.