Periodic Reporting for period 1 - CELESTE (Cryogenic III-V electronics for improved quantum computers)
Berichtszeitraum: 2021-02-01 bis 2023-01-31
The project aims to improve the scalability of quantum computers by developing quantum-tailored cryogenic RF electronics. The overall objectives target the needs of quantum computers in the qubit readout which requires low noise at microwave frequencies and sub-mW ultra-low power consumption. To address this, we performed the design and fabrication of cryogenic quantum-well transistors and RF switches and multiplexers based on III-V transistor technology which leverages unique cryogenic effects to surpass the performance of traditional technologies.
1. Cryogenic InGaAs HEMT with tensile Ohmic contacts - In this work, we have investigated the tensile Ohmic contact in terms of reducing the parasitic source and drain resistances. The results will be published at IEDM 2023 conference proceeding.
2. Self-heating effects - We have investigated the self-heating in the active region with a gate thermometry. In addition, the heat spread adjacent to the active transistors was also investigated with sensing devices.
3. Cryogenic multiplexer and switches - We demonstrated cryogenic switching devices based on III-V HEMT technology for scalable quantum computer control and readout signal routing. This work showed advantages of HEMT-based switching circuits over Si CMOS at cryogenic temperatures for future high-density ultra-low power quantum computer signal routing.
2. Self-heating effects - We have investigated the self-heating in the active region with a gate thermometry. In addition, the heat spread adjacent to the active transistors was also investigated with sensing devices.
3. Cryogenic multiplexer and switches - We demonstrated cryogenic switching devices based on III-V HEMT technology for scalable quantum computer control and readout signal routing. This work showed advantages of HEMT-based switching circuits over Si CMOS at cryogenic temperatures for future high-density ultra-low power quantum computer signal routing.
The impact of a mature quantum computing technology on society is expected to be tremendous, but there are many hurdles to overcome for up-scaling systems. To control and readout large numbers of physical qubits, cryogenic electronics may be necessary to reduce system cost and cabling as well as increase speed. One of the limitations of the design and integration of cryogenic electronics is the power consumption due to the limited cooling power available in the cryostat.
III-V HEMTs are already used in qubit readout LNAs due to their low power and low noise due to high electron mobilities at cryogenic temperatures. This project further demonstrated the scalability of quantum computers by cryogenic RF III-V electronics by a reduction of parasitic resistances with tensile strain Ohmic contacts which would impact future ultra-low power LNAs. In addition, we achieved multiplexing and switches based on the InGaAs HEMT platform which would enable dense and close integration with qubits since the circuits exhibited extremely low power, low charge injection, and fast switching.
III-V HEMTs are already used in qubit readout LNAs due to their low power and low noise due to high electron mobilities at cryogenic temperatures. This project further demonstrated the scalability of quantum computers by cryogenic RF III-V electronics by a reduction of parasitic resistances with tensile strain Ohmic contacts which would impact future ultra-low power LNAs. In addition, we achieved multiplexing and switches based on the InGaAs HEMT platform which would enable dense and close integration with qubits since the circuits exhibited extremely low power, low charge injection, and fast switching.