Josephson Thermal Memory

Abstract

We propose a superconducting thermal memory device that exploits the thermal hysteresis in a flux-controlled, temperature-biased superconducting quantum-interference device (SQUID). This system reveals a flux-controllable temperature bistability, which can be used to define two welldistinguishable thermal logic states. We discuss a suitable writing-reading procedure for these memory states. The time of the memory writing operation is expected to be on the order of ∼ 0.2 ns, for a Nb-based SQUID in thermal contact with a phonon bath at 4.2 K. We suggest a non-invasive readout scheme for the memory states based on the measurement of the effective resonance frequency of a tank circuit inductively coupled to the SQUID. The proposed device paves the way for a practical implementation of thermal logic and computation. The advantage of this proposal is that it represents also an example of harvesting thermal energy in superconducting circuits.arXiv:1706.05323v4 [cond-mat.supr-con]

Josephson-Threshold Calorimeter

“…The thermal response time τ th can be estimated by first-order expanding the heat current terms in Eq. (8) in the idle state of the system [29]. Specifically, it reads τ th = C 2 /(G + K S2IN − K S1IS2 ), where G and K indicate the electron-phonon and electron thermal conductances of the JJ, respectively.…”

“…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.…”

Phase-Tunable Thermal Rectification in the Topological SQUIPT

“…As a response to recent technological developments, the study of thermal transport in nanostructures has received considerable attention during the past decade. Despite the fact that the flow of heat is not easily controlled, many advances, both theoretical and experimental, have been made, laying the foundation of thermal logic [12][13][14][15] and coherent caloritronics [11,[16][17][18][19]. Nonlinear thermal elements, such as thermal diodes that conduct heat well in one direction but poorly in the reversed direction are particularly valuable for both thermal logic [14] and heat management [20].…”

Strong system-bath coupling induces negative differential thermal conductance and heat amplification in nonequilibrium two-qubit systems

“…One long-standing goal is to establish basic units of functional thermal devices for the implementation of heat transport and information processing [6][7][8][9][10]. Many theoretical models have been proposed for thermal operations, ranging from the thermal diode [11][12][13][14], thermal transistor [6,[15][16][17][18][19][20][21][22][23][24], thermal memory [7,25,26] and even thermal computer [8]. And tremendous experiments were conducted to realize these novel thermal operations [27][28][29][30][31][32].…”