Solitonic Josephson-based meminductive systems

Abstract

Memristors, memcapacitors, and meminductors represent an innovative generation of circuit elements whose properties depend on the state and history of the system. The hysteretic behavior of one of their constituent variables, is their distinctive fingerprint. This feature endows them with the ability to store and process information on the same physical location, a property that is expected to benefit many applications ranging from unconventional computing to adaptive electronics to robotics. Therefore, it is important to find appropriate memory elements that combine a wide range of memory states, long memory retention times, and protection against unavoidable noise. Although several physical systems belong to the general class of memelements, few of them combine these important physical features in a single component. Here, we demonstrate theoretically a superconducting memory based on solitonic long Josephson junctions. Moreover, since solitons are at the core of its operation, this system provides an intrinsic topological protection against external perturbations. We show that the Josephson critical current behaves hysteretically as an external magnetic field is properly swept. Accordingly, long Josephson junctions can be used as multi-state memories, with a controllable number of available states, and in other emerging areas such as memcomputing, i.e., computing directly in/by the memory.

Nonlinear Critical-Current Thermal Response of an Asymmetric Josephson Tunnel Junction

“…This is the case of the plethora of works descending only recently [3][4][5][6] from the earlier intuition that a temperature bias imposed across a Josephson junction (JJ) produces a phasedependent heat flow through the device [7]. We are dealing with the phase-coherent caloritronics [5,6,8,9], namely, an emerging research field from which fascinating Josephson-based devices, such as heat interferometers [3,10] and diffractors [4,11,12], heat diodes [13] and transistors [14], solid-state memories [15][16][17], microwave refrigerators [18], thermal engines [19], thermal routers [20,21], heat amplifier [22], and heat oscillator [23], were recently designed and actualized. Even the critical current I c of a Josephson tunnel junction, namely, the maximum dissipationless current that can flow through the device, deviates from the well-known Ambegaokar-Baratoff relation [24] in the presence of a thermal bias imposed across the junction, namely, as the superconducting electrodes reside at different temperatures, as portrayed in Fig.…”

Josephson-Threshold Calorimeter

“…Specifically, we are dealing with solid-state applications in the realm of phase-coherent caloritronics [1,20,21], a research field that promises new ways to coherently master, store, and transport heat at the meso and nanoscopic scale. In fact, different kinds of temperature-based devices, such as heat interferometers [22], diffractors [23,24], diodes [25], transistors [26], memories [27][28][29], logic elements [30], arXiv:1901.01456v3 [cond-mat.supr-con] 28 May 2019 switches [31], routers [32,33], and circulators [34] were recently conceived.…”

Hysteretic Superconducting Heat-Flux Quantum Modulator

“…Specifically, in a SQUID the logical "0" and "1" usually correspond to zero and a single flux quantum in the loop, respectively. More recently, other superconducting tunnel junction-based memory elements were suggested [31][32][33][34][35]. A memory based on a thermally-biased inductive SQUID could take advantage of the clear hysteretic behavior of the temperature of the cold electrode for proper values of the external flux.…”