Research

Cryogenic computing has emerged as one of the most promising alternatives to conventional CMOS technology thanks to their exceptional speed and energy efficiency. Going beyond the classical computing paradigm, the need of suitable cryogenic processing and storage units is felt in the quantum computing field. Currently, in a quantum computer, qubits are placed at extremely low temperatures (tens of milli-Kelvin) to protect their states from noise but the peripheral components (control processor and memory) are placed at room temperature. This necessitates the use of a large number of long cables (for instance, 205 microwave cables for a quantum computer with tens of qubits). To unleash the full potential, the peripheral components must work at cryogenic temperatures to sit beside the qubits. Such a cryogenic processor can also improve the efficiency, reliability, and design complexity of the spacecrafts in aerospace explorations. In my research, I have utilized the unique properties of quantum anomalous Hall effect (QAHE)observed in topological devices, ferroelectric superconducting quantum interference device (FE-SQUID), superconducting memristor, heater cryotron, Josephson junction, and Josephson junction FET to develop suitable and scalable cryogenic memory and logic systems.

While Silicon-based complementary metal-oxide-semiconductor (CMOS) technology has undoubtedly achieved remarkable maturity, empowering us to integrate over a trillion transistors onto a single chip and unleash unprecedented computational power, it has simultaneously ushered in intrinsic limitations owing to the escalating influence of quantum mechanical effects as devices scale down in size. These constraints present formidable obstacles, impeding further advancements in device and circuit performance and rendering them ill-equipped to meet the demands of cutting-edge, data-intensive applications—a challenge exacerbated by the relentless surge in data volumes. To surmount these constraints, my research focuses on the exploration of 'beyond-CMOS' technologies, seeking to usher in a new era of computing platforms. These emerging technologies bring forth both unique advantages and complex challenges. My central research thrust centers on collaborative device and circuit design, representing the most promising avenue for harnessing the untapped potential of these novel technologies. In this regard, I have worked on memristors, ferroelectrics, and phase transition materials to develop better memory and logic systems.

Efficiently managing the ever-expanding volume of data poses a formidable challenge for the electronics industry, primarily because traditional computers require constant data movement between memory and processing units. Google estimates that an approximately 20-42% of energy is devoted to driving the data bus responsible for this data movement. Additionally, the inherent speed mismatch between memory and processing units significantly hampers overall system throughput. A promising solution to these challenges lies in the realm of in-memory computing systems, where computational tasks are executed within the memory array itself. In my research, I have worked with memristive and ferroelectric memory arrays to develop room-temperature in-memory computing systems. I have also worked on cryogenic in-memory computing since in-memory computing at cryogenic environment offers a unique advantage of reducing the cooling cost. I have developed in-memory computing platforms that can perform Boolean logic operations, bit serial addition based on majority logic, binary multiplier, content-addressable memory, matrix-vector multiplication, and ternary computing.

1. Design of Peripheral Components for Quantum Computing


2. Neuromorphic Computing


3. Artificial Intelligence Hardware


4. Probabilistic Computing


5. Hardware Security

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