Superconducting bipolar thermoelectric memory
Thermoelectric superconducting memory working at T<1K, compatible with current quantum processor hardware. The memory encodes a logic state into an output electrical voltage of the order of the superconducting gap, thanks to the presence of a finite thermal difference representing the power supply of the memory itself (bipolar thermoelectric effect). The memory optimizes the quantum processor energy harvesting, solving the quest for a current-controlled superconducting memory with bias output.
Superconducting memory: parallel connection between a bipolar thermoelectric element (BTE) and a resistive load. BTE is a superconducting tunnel junction, with the two sides having different superconducting gaps at different temperatures, with hot temperature on the bigger gap side. With sufficiently opaque tunnelling barriers and sufficiently high temperature difference, BTE develops Seebeck thermovoltages of opposite sign, i.e. ±VS (bipolarity). The opposite values naturally determine the 2 logic states. The current generator, representing the writing/erasing control element of the memory, is applied in parallel to the superconducting memory. It is arranged to send a current pulse ±Ib in the parallel of BTE and the resistive load writing the memory. Indeed, when BTE is thermoactive (generating thermocurrent against the voltage), current flows in the load even when control current is switched-off (Ib=0) determining the voltage drop at the load and consequently the memory logical state. The invention have been demonstrated to work in laboratory as PoC (TRL 3).
- Current controlled superconducting memory for superconducting based quantum processors operating at subKelvin temperatures;
- Embedded (“on-chip”) energy harvesting technology in low temperature quantum processors;
- Embedded multi-bit superconducting RAM technology for superconducting quantum processors.
- Energy harvesting in superconducting quantum processors;
- RAM scalability of superconducting quantum processors technology;
- Integrability with gate-controlled critical current nanodevice to develop fully superconducting classical computation extremely fast;
- Full integrability with superconducting quantum technologies for quantum sensing, communication and simulation.