Spin Microscopy Lab
Nitrogen-vacancy (NV) defects in diamond crystals are playing an essential role in the development of new nanoscale sensing devices based on the quantum properties of NV defects. We are occupied with the following endeavours:
- How can the quantum properties of the NV defect spin be controlled for improved quantum sensing tasks?
- What new nanoscale magnetic field sensing modalities can NV defects enable?
- How can we apply the NV nanomagnetometry toolbox, which offers high sensitivity and high spatial resolution, for the study of magnetic samples such as 2D magnetic materials having nanoscale volumes?
News
Positions available in sponsored project New!
July 2023
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Dr. Phani Kumar gave an invited talk at the Quantum Technologies: Introduction, Materials and Devices conference in IISER, Pune.
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Dr. Phani Kumar gave an invited talk at the Introduction to Precision Measurements and Quantum Metrology conference in ICTS, Bengaluru.
December 2022
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Dr. Phani Kumar gave an invited talk at the Modern Trends in Molecular Magnetism (MTMM) conference in IIT, Kharagpur.
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Ph.D. student Pralekh Dubey presented a poster at the 2nd Asian Conference on Molecular Magnetism in IISER, Bhopal.
March 2022
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Ph.D. student Shashank Kumar gave an online contributed talk at the APS March Meeting in Chicago.
December 2021
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Dr. Phani Kumar gave an online invited talk at the conference MRSI AGM 2021.
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Dr. Phani Kumar gave an online contributed talk at the National Conference on Quantum Condensed Matter.
Dr. Phani Kumar
Principal Investigator
Research Interests
Nitrogen-vacancy (NV) spins in diamond, Quantum sensing, Atomic force microscopy, Nano-spin-mechanical systems (NSMS), Nanomagnetism, Hybrid quantum sensors, Nanoscale scanning diamond probes, Magnetic resonance imaging, Biosensing, Quantum technology, Confocal microscopy, Laser interferometry
Academics
Postdoc [July 2013 - November 2017]
Institute for Quantum Optics, University of Ulm, Germany
Advisor: Prof. Fedor Jelezko
Research: Quantum Sensing, Diamond Magnetometry, Nano-spin-mechanical Systems (NSMS)
Section on Quantum Physics and Information Technology, Technical University of Denmark, Copenhagen
Advisor: Prof. Ulrik Andersen
Research: Nanomechanics
Division of Physics and Applied Physics, Nanyang Technological University, Singapore
Research: Spin Centers in Silicon Carbide
PhD
[Department of Physics, University of Basel, Switzerland (April 2009 - June 2013)]
Thesis: Magnetic resonance force microscopy: Harnessing nuclear spin fluctuations.
Advisor: Prof. Martino Poggio
Research: Apart from making contributions to setting up of a low temperature high vacuum
magnetic resonance
force microscopy (MRFM) setup, I explored a novel approach using MRFM to harness the naturally occurring
random
fluctuations in nanoscale ensembles of nuclear spins.
MSc
[Micro and Nanosystems, ETH Zurich, Switzerland (October, 2006 - January, 2009)]
Thesis: Efficient coupling to photonic crystal cavities.
Advisor: Prof. Atac Imamoglu
Courses Credited:
Quantum Mechanics for Nanosystems, Advanced Optoelectronics, Quantum Optics, Quantum Systems for
Information Technology,
Magnetism: from the Atom to the Solid State, Advanced Solid State Physics, Statistical Physics,
Semiconductor Nanostructures,
Quantum Optics and Semiconductor Quantum Dots
Course Projects:
MATLAB simulations for gain calculations of quantum dot laser
BTech
[Indian Institute of Technology, Madras (September, 2001 - July, 2005)]
Courses Credited: (GPA - 8.56/10)
Physics - I, Physics Lab - I, Electrodynamics, Physics Lab - II, Quantum Mechanics for Engineers,
Semiconductor
Physics, Dynamical Systems, Laser Theory, Mathematical Physics, Superconductivity and its Applications
Achievements
- Pratibha scholarship awarded by Andhra Pradesh state government for BTech studies in IIT Madras
- Indian Institutes of Technology-Joint Entrance Examination (IIT-JEE) 2001 Rank: 532 (out of 1,70,000+ students) for admission to IITs
- Secured an All India Rank of 8 (99.81 percentile) in Joint Entrance Screening Test (JEST) Physics 2009 for admission to Ph.D programmes
- Achieved a score of 890/1000 (90 percentile) in GRE Physics 2005, an examination taken by applicants for admission into graduate schools in USA
Research
SINGLE-SPIN MAGNETOMETRY
We develop nitrogen-vacancy (NV) spin-based diamond magnetometers capable of measuring the minute magnetic fields with high sensitivity and spatial resolution. Our aim is to utilize the diamond spins as scanning probes to spatially map the tiny magnetic fields on the nanoscale. This would allow us to obtain a greater understanding of the magnetic phenomena which are otherwise not discerned by global magnetization measurements due to spatial averaging.
HYBRID NV-DIAMOND SENSORS
We also apply NV centers as nanoscale probes of stress, temperature and electric fields. Standard NV-diamond sensing devices when combined with the strategy of hybridization offer a huge potential for improving their sensitivity. Such hybrid quantum sensors may provide a novel approach for studying a broad range of physical processes on the nanoscale.
Publications
High-resolution spectroscopy of a single nitrogen-vacancy defect at zero magnetic field
Quantum Sci. Technol., 2023, 8, 025011 pdf
Scalable fabrication of single silicon vacancy defect arrays in silicon carbide using focused ion beam
ACS Photonics, 2017, 4(5), 1054-1059
Nanomechanical sensing using spins in diamond
Nano Lett. (2017), 17 (3), 1496-1503
Boundary between the thermal and statistical polarization regimes in a nuclear spin ensemble
Appl. Phys. Lett.105, 043112 (2014)
Harnessing nuclear spin polarization fluctuations in a semiconductor nanowire
Nature Physics 9, 631-635 (2013)
Feedback cooling of cantilever motion using a quantum point contact transducer
Appl. Phys. Lett. 101, 133104 (2012)
Measurement of statistical nuclear spin polarization in a nanoscale GaAs sample
Phys. Rev. B 84, 205328 (2011)
A geometry for optimizing nanoscale magnetic resonance force microscopy
Appl. Phys. Lett. 98, 163103 (2011)
Teaching
PHY 201 Waves and Optics: August, 2018 - November, 2018
PHY 627 Quantum Engineering: January, 2019 - April, 2019
PHY 209 Electromagnetism: August, 2019 - November, 2019
PHY 627 Quantum Engineering: January, 2020 - April, 2020
PHY 625 Quantum Information Theory: August, 2020 - December, 2020
PHY 106 Quantum Physics: April, 2021 - June, 2021
PHY 627 Quantum Engineering: August, 2021 - November, 2021
PHY 402 Atomic and Molecular Physics: January, 2022 - April, 2022
PHY 201 Waves and Optics: August, 2022 - November, 2022
PHY 640 Classical and Quantum Optics: January, 2023 - April, 2023
PHY 403 Condensed Matter Physics: August, 2023 - November, 2023
PHY 640 Classical and Quantum Optics: January, 2024 - April, 2024
Members
PhD Students
Name: Shashank Kumar
Email: shashankk19[AT]iiserb.ac.in
Joined: January, 2020
Name: Pralekh Dubey
Email: dpralekh[AT]iiserb.ac.in
Joined: August, 2021
BS-MS Students
Name: Yash Patel
Email: yash19[AT]iiserb.ac.in
Joined: September, 2023
Name: Devang V Krishnan
Email: devang19[AT]iiserb.ac.in
Joined: June, 2023
Project Fellow
Name: Anshul Poonia
Email: anshulpoonia1996@gmail.com
Joined: June, 2023
Alumni
BS-MS Students
- Alen Philip (Graduated from IISERB in 2019, Currently Graduate Student at the Institute of Optics, University of Rochester)
- Basim S. S. (Graduated from IISERB in 2019)
- Md Arshad (Graduated from IISERB in 2020)
- Subham Singh (Graduated from IISERB in 2020)
- Ritesh Kumar Singh (Graduated from IISERB in 2020)
- Sujeet Pani (Graduated from IISERB in 2021, Currently Graduate Student at the Center for Quantum Information and Control, University of New Mexico)
- Swayangprabha Shaw
- Sudhan Bhadade (Graduated from IISERB in 2022, Currently Graduate Student at the Center for Quantum Information and Control, University of New Mexico)
- Jemish Naliyapara (Graduated from IISERB in 2023)
- Dershik Ayyathan (Graduated from IISERB in 2023, Currently Graduate Student at the Department of Physics, The Technical University of Munich)
