TY - JOUR
T1 - Nanopatterning of weak links in superconducting oxide interfaces
AU - Singh, Gyanendra
AU - Lesne, Edouard
AU - Winkler, Dag
AU - Claeson, Tord
AU - Bauch, Thilo
AU - Lombardi, Floriana
AU - Caviglia, Andrea D.
AU - Kalaboukhov, Alexei
PY - 2021
Y1 - 2021
N2 - The interface between two wide band-gap insulators, LaAlO3 and SrTiO3 (LAO/STO), hosts a quasi-two-dimensional electron gas (q2DEG), two-dimensional superconductivity, ferromagnetism, and giant Rashba spin-orbit coupling. The co-existence of two-dimensional superconductivity with gate-tunable spin-orbit coupling and multiband occupation is of particular interest for the realization of unconventional superconducting pairing. To investigate the symmetry of the superconducting order parameter, phase sensitive measurements of the Josephson effect are required. We describe an approach for the fabrication of artificial superconducting weak links at the LAO/STO interface using direct high-resolution electron beam lithography and low-energy argon ion beam irradiation. The method does not require lift-off steps or sacrificial layers. Therefore, resolution is only limited by the electron beam lithography and pattern transfer. We have realized superconducting weak links with a barrier thickness of 30–100 nm. The barrier transparency of the weak links can be controlled by the irradiation dose and further tuned by a gate voltage. Our results open up new possibilities for the realization of quantum devices in oxide interfaces.
AB - The interface between two wide band-gap insulators, LaAlO3 and SrTiO3 (LAO/STO), hosts a quasi-two-dimensional electron gas (q2DEG), two-dimensional superconductivity, ferromagnetism, and giant Rashba spin-orbit coupling. The co-existence of two-dimensional superconductivity with gate-tunable spin-orbit coupling and multiband occupation is of particular interest for the realization of unconventional superconducting pairing. To investigate the symmetry of the superconducting order parameter, phase sensitive measurements of the Josephson effect are required. We describe an approach for the fabrication of artificial superconducting weak links at the LAO/STO interface using direct high-resolution electron beam lithography and low-energy argon ion beam irradiation. The method does not require lift-off steps or sacrificial layers. Therefore, resolution is only limited by the electron beam lithography and pattern transfer. We have realized superconducting weak links with a barrier thickness of 30–100 nm. The barrier transparency of the weak links can be controlled by the irradiation dose and further tuned by a gate voltage. Our results open up new possibilities for the realization of quantum devices in oxide interfaces.
KW - Laalo/SrTiO interface
KW - Nanopatterned materials
KW - Top-down lithography
KW - Two-dimensional superconductivity
UR - http://www.scopus.com/inward/record.url?scp=85100249080&partnerID=8YFLogxK
U2 - 10.3390/nano11020398
DO - 10.3390/nano11020398
M3 - Article
AN - SCOPUS:85100249080
SN - 2079-4991
VL - 11
SP - 1
EP - 11
JO - Nanomaterials
JF - Nanomaterials
IS - 2
M1 - 398
ER -