ECE Ph.D. Student Randy Kwende Tallies Second-place Finish in IEEE Paper Competition

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Randy Kwende

Ph.D. student Randy Kwende of the UMass Amherst Electrical and Computer Engineering (ECE) Department placed second in the prestigious Student Paper Competition during the 2024 International Microwave Symposium (IMS), held from June 17th to 20th in Washington, D.C. The symposium was organized and staged by the Institute of Electrical and Electronics Engineers (IEEE) Microwave Theory and Technology Society. Kwende does his research in the UMass Amherst Quantum RF Group, directed by ECE Professor Joseph Bardin. 

As Bardin announced, “Very proud of my Ph.D. student Randy Kwende for winning second place out of 301 eligible student papers in the student paper contest at IMS 2024! His paper, ‘A 6mW Cryogenic SIGe Receiver for High-Fidelity Qubit Readout,’ describes a low-noise, cryogenic, integrated circuit that enabled a readout fidelity of 99 percent for a cavity-coupled transmon qubit.”

As Kwende explained about his prize-winning paper, “To the best of the authors’ knowledge, this is the first system that entirely replaces an indium phosphide (InP), high-electron mobility transistor (HEMT), low-noise-amplifier-based receiver chain with a silicon readout integrated circuit.”

Kwende concluded that “This demonstration represents an important step in the realization of fully integrated, large-scale, cryogenic qubit control systems.”

The National Science Foundation supported Kwende’s award-winning research and much additional research with a $406,000 award for a proposal titled “Radio Frequency Integrated Circuits for Scalable Control of Quantum Processors,” in which Bardin was the principal investigator. 

As Bardin has described the research in his group, “We perform basic research on complementary metal–oxide–semiconductor (CMOS) and BiCMOS integrated electronics to control and measure quantum devices such as qubits, single-photon detectors, and Terahertz mixers. A common theme is that our devices are optimized to work at very low temperatures, often in the range of four to 20 degrees above absolute zero.”

In addition, ECE Ph.D. student Zhenjie Zou was named one of the 10 finalists in the competition for his paper “A 1.6 mW Cryogenic SiGe LNA IC For Quantum Readout Applications Achieving 2.6 K Average Noise Temperature from 3–6 GHz.” Zou is also a member of the UMass Amherst Quantum RF Group, and he is co-advised by Bardin and Sanjay Raman, ECE Professor and Dean of the College of Engineering. Zou's research focuses on wideband discrete-time high linearity receivers, low noise and low power consumption circuit design for wireless transceiver applications, and cryogenic circuit design for quantum computing. 

Kwende received his B.Sc. in Electrical Engineering in 2012 from the University of Massachusetts, Lowell. He then joined RF Micro Devices, Inc. (name later changed to Qorvo) as a design engineer for their Cellular Base-station Business Unit, where he worked on custom radio-frequency, front-end components for receivers for three years. 

Kwende has been with the UMass Amherst Quantum RF group since 2015. His research focus is on the design of cryogenic, semiconductor, mixed-signal, interface integrated circuits for superconducting devices such as nanowires used in single-photon detection and Josephson-junction-based qubits for quantum computing. (July 2024)