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Yashna Lekhai

I am studying for a PhD under the supervision of Dr. Gavin Morley in the Diamond group at Milburn House, with funding from NQIT. The project is concerned with fabricating laser-written diamond devices for use in quantum technologies.

I completed an undergraduate physics degree at the University of Surrey including a placement at Radboud University, Nijmegen, the Netherlands working on electron-phonon coupling in low-dimensional systems.

Current Research

The nitrogen-vacancy defect in diamond has great potential for use a a qubit due to its spin-triplet ground and first-excited states. Using a new technique developed by our collaborators in Oxford, these defects can be placed with high accuracy at any depth within a diamond sample. Laser written defects have been shown to be well isolated and have incredibly long coherence times. Additionally, the same technique is capable of creating conductive tracks of graphitic material inside the diamond with little surrounding damage. Several samples have been created to test the limits of this, with the aim of using the wire tracks as both DC and MW circuitry to manipulate single defects, essentially creating many individually adressable qubits on a single diamond 'chip'. In order to connect these graphitic wires to conventional circuit elements, we are developing photolithographic techniques to pattern gold electrical contacts on the surface of the diamond, connecting to the wires that protrude to the top face.

Laser written electrodes in a diamond (taken using a confocal microscope)

Electrically contactde diamond


[1] C.J. Stephen et al.,Deep Three-Dimensional Solid-State Qubit Arrays with Long-Lived Spin Coherence, Phys. Rev. App., 12, 6 (2019)

[2] Y.-C. Chen et al., Laser writing of coherent colour centres in diamond, Nature Photonics 11, 77 (2016)

[3] Y.-C. Chen et al., Laser writing of individual atomic defects in a crystal with near-unity yield, arXiv:1807.04028 (2018)

Social Media

Twitter: @YashnaLekhai

Instagram: @Lekhy8