Related papers: Experimental demonstration of a Josephson magnetic…
Josephson junctions containing two ferromagnetic layers are being considered for use in cryogenic memory. Our group recently demonstrated that the ground-state phase difference across such a junction with carefully chosen layer thicknesses…
The $\varphi$ Josephson junction has a doubly degenerate ground state with the Josephson phases $\pm\varphi$. We demonstrate the use of such a $\varphi$ Josephson junction as a memory cell (classical bit), where writing is done by applying…
We demonstrate a Josephson junction with a weak link containing two ferromagnets, with perpendicular magnetic anisotropy and independent switching fields in which the critical current can be set by the mutual orientation of the two layers.…
Arrays of Vortex Transitional (VT) memory cells with functional density up to $1 Mbit/cm^2$ have been designed, fabricated, and successfully demonstrated. This progress is due to recent advances in design optimization and in superconductor…
We present a new study of magnetic structures with controllable effective exchange energy for Josephson switches and memory. As a basis for a weak link we propose to use a periodic structure comprised of ferromagnetic (F) layers spaced by…
Josephson junctions containing ferromagnetic layers have generated interest for application in cryogenic memory. In a junction containing both a magnetically hard fixed layer and soft free layer with carefully chosen thicknesses, the…
The physics of the "Pi" phase shift in ferromagnetic Josephson junctions enables a range of applications for spin-electronic devices and quantum computing. In this respect our research is devoted to the evaluation of the best materials for…
Superconductivity and ferromagnetism are antagonistic forms of order, and rarely coexist. Many interesting new phenomena occur, however, in hybrid superconducting/ferromagnetic systems. For example, a Josephson junction containing a…
With the ever-increasing energy need to process big data, the realization of low-power computing technologies, such as superconducting logic and memories, has become a pressing issue. Developing fast and non-volatile superconducting memory…
Josephson junctions are currently used as base elements of superconducting logic systems. Long enough junctions subject to magnetic field host quantum phase 2{\pi}-singularities - Josephson vortices. Here we report the realization of the…
We report the fabrication and testing, at 4.2 K, of an SISFS device, where S, F, and I denote a superconductor (Nb), a ferromagnetic material (permalloy), and an insulator (AlOx), respectively. The F layer covers about one half of the top…
Josephson junctions containing ferromagnetic materials have attracted intense interest both because of their unusual physical properties and because they have potential application for cryogenic memory. There are two ways to store…
We theoretically study the Josephson effect in a superconductor/normal metal/superconductor ({\it S}/{\it N}/{\it S}) Josephson junction composed of $s$-wave {\it S}s with {\it N} which is sandwiched by two ferromagnetic insulators ({\it…
We propose a non-volatile memory element based on a lateral ferromagnetic Josephson junction with spin-orbit coupling and out-of-plane magnetization. The interplay between the latter and the intrinsic exchange field of the ferromagnet leads…
We propose a novel Josephson device in which 0 and $\pi$ states are controlled by an electrical current. In this system, the $\pi$ state appears in a superconductor/normal metal/superconductor junction due to the non-local spin accumulation…
Superconducting devices, which rely on modulating a complex superconducting order parameter in a Josephson junction, have been developed for low power logic operations, high-frequency oscillators, and exquisite magnetic field sensors.…
We fabricated high quality Nb/Al_2O_3/Ni_{0.6}Cu_{0.4}/Nb superconductor-insulator-ferromagnet-superconductor Josephson tunnel junctions. Using a ferromagnetic layer with a step-like thickness, we obtain a 0-pi junction, with equal lengths…
Josephson junctions with ferromagnetic layers are vital elements in a new class of cryogenic memory devices. One style of memory device contains a spin valve with one "hard" magnetic layer and one "soft" layer. To achieve low switching…
Due to the ever increasing power and cooling requirements of large-scale computing and data facilities, there is a worldwide search for low-power alternatives to CMOS. One approach under consideration is superconducting computing based on…
Motivated by recent progress in development of cryogenic memory compatible with single flux quantum (SFQ) circuits we have performed a theoretical study of magnetic SIsFS Josephson junctions, where 'S' is a bulk superconductor, 's' is a…