Josephson Effect in Hybrid Oxide Heterostructures with an Antiferromagnetic Layer

Abstract

Josephson coupling between an s- and d-wave superconductor through a 50 nm thick Ca1-xSrxCuO2 antiferromagnetic layer was observed for the hybrid Nb/Au/Ca1-xSrxCuO2/YBa2Cu3O7-delta heterostructures and investigated as a function of temperature, magnetic field, and applied millimeter-wave electromagnetic radiation. The magnetic field dependence of the supercurrent I(c)(H) exhibits anomalously rapid oscillations, which is the first experimental evidence of the theoretically predicted giant magneto-oscillations in Josephson junctions with antiferromagnetic interlayers.

Magnetic proximity effect and superconducting triplet correlations at the cuprate superconductor and oxide spin valve interface

“…As shown by the additional measurements, the resistance of the two-layer Au-Nb film is also small. 62 As a result, in the temperature range T < T YBCO c the resistance of the mesastructure is combined with the resistance of the interfaces between the boundaries between materials YBCO/SRO, SRO/LSMO,LSMO/Au:…”

“…This is confirmed by the presence of Shapiro step oscillations in response to microwave power, the amplitudes of which are in good agreement with the resistively shunted Josephson junction model. 62 The absence of "short-circuiting" is ensured by a sufficiently thick interlayers, wherein the roughness of the layers is much less than the thickness of LSMO and SRO films.…”

“…A comparison of the experimental Shapiro steps with those calculated according to the modified resistive model 62 allows us to determine the CPD of the mesastructure critical current. Measurement of the current-phase dependence was conducted in a zero magnetic field, and during mesastructure cooling in a constant magnetic field (100-200 Oe), parallel to the substrate plane, starting from a temperature of 160 K.…”

“…11(a)) clearly points to the non-sinusoidal nature of the current-phase dependence. 62 Fig. 11(b) shows the experimental and theoretical dependences of the critical current I c and the first Shapiro step I 1 on the normalized values of the microwave current x ¼ I RF /I c x wherein I RF is the amplitude of the microwave current x ¼ f e /f c .…”

Suppression of superconductivity in Nb by IrMn in IrMn/Nb bilayers

“…Compared to the AFM/FM and FM/S interfaces, however, the amount of work on antiferromagnet/superconductor (AFM/S) heterointerfaces is quite limited. [8][9][10][11][12][13][14][15][16] Since the classic work of Hauser et al on Pb/Cr bilayers, 9 several investigations have been carried out on AFM/S junctions using different combinations of antiferromagnets and superconductors, including Nb/Cr multilayer, 10 Cr/V/Cr trilayer, 11 and Nb/c-FeMn bilayer structures. 12 Key findings reported so far include suppression of critical temperature (T c ) of S by the AFM [10][11][12] and existence of Josephson current in S/AFM/S trilayer structures.…”