Voltage-controlled Cryogenic Boolean Logic Family Based on Ferroelectric SQUID

TL;DR

This paper introduces a novel voltage-controlled cryogenic logic family based on ferroelectric SQUIDs, enabling efficient, all-cryogenic Boolean logic operations suitable for quantum computing and space applications.

Contribution

It proposes a ferroelectric SQUID (FeSQUID) device for voltage-controlled logic gates, overcoming challenges of traditional superconducting devices in cryogenic environments.

Findings

FeSQUID exhibits two critical current levels controlled by ferroelectric polarization.

Designed and verified Boolean logic gates (Copy, NOT, AND, OR) using FeSQUID.

Simulated a 2-input XOR gate demonstrating logic family capabilities.

Abstract

The recent progress in quantum computing and space exploration led to a surge in interest in cryogenic electronics. Superconducting devices such as Josephson junction, Josephson field effect transistor, cryotron, and superconducting quantum interference device (SQUID) are traditionally used to build cryogenic logic gates. However, due to the superconducting nature, gate-voltage-based control of these devices is extremely difficult. Even more challenging is to cascade the logic gates because most of these devices require current bias for their operation. Therefore, these devices are not as convenient as the semiconducting transistors to design logic gates. Here, to overcome these challenges, we propose a ferroelectric SQUID (FeSQUID) based voltage-controlled logic gates. FeSQUID exhibits two different critical current levels for two different voltage-switchable polarization states of the ferroelectric. We utilize the polarization-dependent (hence, voltage-controllable) superconducting to resistive switching of FeSQUID to design Boolean logic gates such as Copy, NOT, AND, and OR gates. The operations of these gates are verified using a Verilog-A-based compact model of FeSQUID. Finally, to demonstrate the fanning out capability of FeSQUID-based logic family, we simulate a 2-input XOR gate using FeSQUID-based NOT, AND, and OR gates. Together with the ongoing progress on FeSQUID-based non-volatile memory, our designed FeSQUID-based logic family will enable all-FeSQUID based cryogenic computer, ensure minimum mismatch between logic and memory blocks in terms of speed, power consumption, and fabrication process.