Non-destructive Nanostructuring: Using a Focused Helium Ion Beam to Change the Properties of Cuprate Superconductors

Description

Nanostructuring of thin film materials has increasingly drawn attention throughout the last years. One application is the production of pinning structures for magnetic flux quanta in superconductors, such as holes in a thin film or defects in the material. While such structures can be created by lithographic techniques in classical superconductors, their applicability in the
cuprate high-critical temperature superconductors is limited since these materials are prone to oxygen loss. This demands a method of locally suppressing superconductivity without damaging the film’s surface.
One method suitable for achieving this goal is irradiation with 30 keV helium ions, which suppresses the superconductor’s critical temperature T in the irradiated region while preserving the material’s crystal structure. Here, we present ultra-dense regular structures for pinning magnetic flux quanta in the high-temperature superconductor YBa₂Cu₃O_7-δ (YBCO) created by irradiation in a helium ion microscope. Systematic studies show that the superconductor’s electronic transport properties depend on the irradiation fluence and enable
us to perform computer simulations of T_c-suppression that are calibrated with experimental data. Having a technique for locally reducing the critical temperature of YBCO to a desired value opens up a vast range of possibilities for manipulating magnetic flux quanta, which has, for example, led to an ordered Bose glass phase [1,2] in thin films structured with this method.
Altogether, this establishes the method of irradiation in a helium ion microscope as a promising and versatile tool for creating dense and complex structures in high-T_c superconductors, which could be an important step on the way toward low-dissipative superconducting electronics.
[1] L. Backmeister B. Aichner, M. Karrer, K. Wurster, R. Kleiner, E. Goldobin, D. Koelle, W. Lang, "Ordered Bose Glass of Vortices in Superconducting YBa Cu O
Thin Films with a Periodic Pin Lattice Created by Focused Helium Ion Irradiation", Nanomaterials, 12, 3491, (2022).
[2] B. Aichner, L. Backmeister, M. Karrer, K. Wurster, R. Kleiner, E. Goldobin, D. Koelle, W. Lang, "Angle-dependent Magnetoresistance of an Ordered Bose Glass of Vortices in YBa₂Cu₃O_7-δ Thin Films with a Periodic Pinning Lattice", Condens. Matter 8, 32 (2023).

Period	15 Sep 2023
Event title	IEEE International Conference: Nanomaterials, Applications and Properties
Event type	Conference
Location	Bratislava, SlovakiaShow on map
Degree of Recognition	International