Research

Spintronic materials and devices for computing and machine intelligence:

We work on innovative materials and nanoscale devices which go far beyond existing ones in energy efficiency, speed, and integration density. In particular, here we use materials and devices that couple electrons' spin and charge properties, also called spintronic devices. Our goal is to beat today's performance, energy, and scaling limits of data storage, memory, and computing devices, each by 100x. For example, can we build memories that simultaneously operate at pico-Second read/write, atto-Joule per bit operation, and at few-nanometer scales? This work involves new materials development, understanding of physics of thin films and interfaces, and their consequent electrical and magnetic behavior. 

Read more:

• • Electrically Controlled All-Antiferromagnetic Tunnel Junctions on Silicon with Large Room-Temperature Magnetoresistance, Advanced Materials, 2024.

  • Observation of current-induced switching in non-collinear antiferromagnetic IrMn3 by differential voltage measurements, Nature Communications, 2021. 

  • Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with a vertical composition gradient, Nature Communications, 2021. 

  • Electrical manipulation of the magnetic order in antiferromagnetic PtMn pillars, Nature Electronics, 2020.

  • Switching of perpendicular magnetization by spin–orbit torques in the absence of external magnetic fields, Nature Nanotechnology, 2014.

Unconventional computing architectures:

Here we focus on using the new devices which we develop, in novel architectures for computing systems, and to realize circuits/architectures where new intelligent functionalities emerge from the physics. We work closely with industry and interact across disciplines, to develop the hardware, tools and ecosystems to translate device/circuit advances into applications.

Read more:

• • Probabilistic computing with voltage-controlled dynamics in magnetic tunnel junctions, Nanotechnology, 2023.

  • Reconfigurable Physically Unclonable Functions Based on Nanoscale Voltage‐Controlled Magnetic Tunnel Junctions, Advanced Electronic Materials, 2023. 

  • Implementation of Artificial Neural Networks using Magnetoresistive Random-Access Memory-based Stochastic Computing Units", IEEE Magnetics Letters, 2021.

Microwave, magnonic, and quantum devices: 

We are also interested in using spintronic effects to build microwave, radio-frequency, and sensing devices. Examples are record-small electronic oscillators using spin-torque, record-sensitive detectors of microwave radiation, and magnonic devices based on spin waves, which are the collective excitations of spins in a magnetically ordered material.

Read more:

• • Micromagnetic investigation of a voltage-controlled skyrmionic magnon switch, Physical Review Applied, 2022. 

  • A 3 pJ/bit free space optical interlink platform for self-powered tetherless sensing and opto-spintronic RF-to-optical transduction, Scientific Reports, 2021.

  • Giant spin-torque diode sensitivity in the absence of bias magnetic field, Nature Communications, 2016.