Speaker: Prof. Jayasimha Atulasimha, Professor, Mechanical and Nuclear Engineering, 
Virginia Commonwealth University Richmond, Virginia, USA. 

Title: "Quantum control of spin qubits with classical nanomagnets".

Date: Friday, 31st July 2026 - Time: 4 PM

Hi-Tea & Coffee: 5 PM

Venue: CeNSE Seminar Hall

Abstract:
Our group has demonstrated energy-efficient electrical control of nanoscale magnetisation 
dynamics using strain-mediated voltage control [1], and voltage control of magnetic anisotropy 
[2] in nanomagnets and skyrmions, respectively. These have found applications in implementing 
non-volatile memory [1,2] and neuromorphic computing [3]. However, such nanomagnets can generate 
highly confined microwaves to control the quantum state of proximally located spin qubits.

This talk will discuss the use of microwaves generated by voltage-controlled magnetisation dynamics 
in nanomagnets [4]to implement single-qubit quantum gates with fidelities approaching state-of-the-art 
[4] in a scalable manner. We will also discuss recent experiment work demonstrating coherent quantum 
control of a single nitrogen vacancy (NV) centre in diamond with microwave fields generated from
proximally located shape-anisotropic nanomagnets of lateral dimensions down to 200 nm x 180 nm, 
driven remotely by surface acoustic wave (SAW) excitation [5]. Specifically, high-contrast Rabi 
oscillations have been demonstrated. Additionally, we report relaxometry using microwave pulses 
generated by such proximally located nanomagnets that can be orders of magnitude more efficient 
than using a conventional antenna [5].  Such localised and energy-efficient control has potential 
to lead to scalable quantum computing and sensing with NV defects in diamond and other spin qubits.

Finally, we have shown that it is possible to control of spin qubits using SOT-driven nanomagnets [6] 
that are at least an order of magnitude more efficient and have higher gate speeds than conventional 
Electron Spin Resonance (ESR) driven spin qubits, while they have gate speeds comparable to Electron 
Dipole Spin Resonance (EDSR) driven spin qubits with an order of magnitude higher coherence times [6].

References

[1] Nano Letters, 16, 1069, 2016; ACS Applied Materials & Interfaces, 17, 48, 65946, 2025.

[2] Nature Electronics 3, 539, 2020.

[3] Neuromorph. Comput. Eng. 2 044011, 2022; Nano Lett., 25, 42, 15369, 2025

[4] Communication Physics 5, 284, 2022; Phys. Rev. Applied 22, 064077, 2024.  

[5] Nature Communications (2026). https://doi.org/10.1038/s41467-026-73087-z
[6] https://arxiv.org/abs/2606.00824
Acknowledgement: This work was funded by the US National Science Foundation ExpandQISE grant # 2231356

Biography:
Jayasimha Atulasimha is an Engineering Foundation Professor of Mechanical and Nuclear Engineering 
with a courtesy/affiliate appointment in Electrical and Computer Engineering and Physics at the 
Virginia Commonwealth University (VCU) where he is also the Associate Director for Research and 
Innovation for the Institute for Sustainable Energy and Environment (ISEE). His current research 
interests include nanomagnetism, spintronics, non-volatile memory, hardware AI and quantum computing. 
He is a fellow of the ASME, an IEEE Senior Member and past chair of the Technical Committee on 
Spintronics, IEEE Nanotechnology Council. He has been a summer visiting faculty at the 
Indian Institute of Science Quantum Technology Initiative (IQTI) since 2022.

Host Faculty:  Prof. Ambarish Ghosh