Spin-orbitronics Device Research Group

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Dr. Rik Dey
Assistant Professor

I am an Assistant Professor in the Department of Electrical Engineering at IIT Kanpur in the Microelectronics and VLSI stream. I had completed my Masters and PhD in Electrical and Computer Engineering from the University of Texas at Austin in 2014 and 2019, respectively, with specializations in Solid State Electronics. I received my B. Tech. degree in Electrical Engineering from IIT Kanpur in 2012. I was a Post-Doctoral Fellow at the University of Texas Austin before joining as an Assistant Professor at IIT Kanpur in 2020.

My primary research interest includes theoretical modelling of electrical transport and magnetic behavior in strong spin-orbit coupled materials, transition metal chalcogenides, transition metal dichalcogenides and topological insulators. I am currently working on modelling of coupled charge-spin transport in these materials and current induced magnetization switching mechanism on nanomagnets in proximity to these materials. The main objective of my research is to analyze the performance of these novel material-based spin-orbitronics devices for beyond spin transfer torque magnetic random access memory (beyond STT MRAM) applications. On the experimental side, I am setting up a lab for chemical vapor deposition (CVD) growth as well as magnetic and electrical characterization of transition metal dichalcogenide-based spin-orbitronics devices for spin orbit torque magnetic random access memory (SOT MRAM) applications. I also am working on modelling of electrostatics and charge transports in beyond Fin Field Effect Transistor (beyond FinFET) devices, such as nanosheets and forksheets transistors.

Research Area: Nanoelectronics, Magnetism, Spintronics

Topological Insulators

Topological insulators (TIs) are unique materials with insulating bulk and metallic surface states. The surface states of a TI have spin-momentum locked Dirac-type band structure due to strong spin-orbit coupling. The spin-momentum locking of the surface states provides an opportunity for manipulating the coupled spin and charge degrees of freedom of electrons on the surface of a TI by controlling one or the other. The charge current-induced spin polarization of the surface states and subsequent diffusion or tunnelling of spin current in an adjacent material, or conversion of spin current to charge current on the surface of a TI, are a few among many effects of this spin-momentum locking, which renders TIs as promising candidates for low-power spintronic applications. My research interests include theoretical modelling of TI-ferromagnet and TI-antiferromagnet based spin-orbitronics devices and subsequent experimental studies to optimize the device performances.

Two-dimensional Materials

Transition metal chalcogenides (TMCs) and di-chalcogenides (TMDs) are two-dimensional materials with varying electric and magnetic properties, which provide platform for two-dimensional electronics and spintronics applications. TMCs can be ferromagnetic to antiferromagnetic depending on the structural compositions, and TMDS have high spin-orbit coupling suitable for spin-charge conversion. I am interested in theoretical modelling and experimental realizations of TMD based spin-orbitronics devices, as well as ab-initio calculations of TMC materials for achieving above room-temperature magnetic behavior.

For motivated undergraduates, masters and PhD students: If you are interested in my research area and want to work in my group, please contact me.

Sponsored Projects:

Funding Agency Grant Name Grant Amount Date & Duration Role
Science and Engineering Research Board Start-up Research Grant 33 lakhs Jan 2022 - Jan 2024 (2 years) PI
IIT Kanpur Initiation Grant 25 lakhs Dec 2020 - Dec 2023 (3 years) PI

PhD Students:

Name Date Co-Supervisor
Sanjay Sharma Ongoing Prof. S. Sahay
Vinod Naik Bhukya Ongoing Prof. Y. S. Chauhan

Masters Students:

Name Date Co-Supervisor
Kolla Mohan Vamsi Ongoing -
Abhay Singh Ongoing -
Korrapadu Ushaswi Ongoing -

Undergrad Interns:

Name Date Program
Diksha (B. Tech.) Summer 2022 SURGE, IIT Kanpur
N Bhuvan (B. Tech.) Summer 2021 SURGE, IIT Kanpur
Aditya Gupta (B. Tech.) Summer 2021 SURGE, IIT Kanpur
Tarun Agarwal (B. Tech.) Summer 2021 SURGE, IIT Kanpur

Journal Publications:

  1. R. Dey, A. Roy, L. F. Register, S. K. Banerjee, Recent progress on measurement of spin–charge interconversion in topological insulators using ferromagnetic resonance, APL Materials, 9 (6), 060702 (2021).
  2. R. Dey, L. F. Register, S. K. Banerjee, Two-dimensional transport model of spin-polarized tunneling in a topological-insulator/tunnel-barrier/ferromagnetic-metal heterostructure, Physical Review B, 102, 144414 (2020).
  3. A. Roy, R. Dey, T. Pramanik, A. Rai, R. Schalip, S. Majumder, S. Guchhait, S. K. Banerjee, Structural and magnetic properties of molecular beam epitaxy grown chromium selenide thin films, Physical Review Materials, 4, 025001 (2020).
  4. R. Dey, L. F. Register, S. K. Banerjee, Theory of spin detection on the surface of diffusive topological insulators by means of ferromagnets: Establishing Onsager reciprocity and the importance of tunnel contact, Physical Review B, 100, 094419 (2019).
  5. R. Dey, N. Prasad, L. F. Register, S. K. Banerjee, Conversion of spin current into charge current in a topological insulator: Role of the interface, Physical Review B, 97, 174406 (2018).
  6. R. Dey, L. F. Register, S. K. Banerjee, Modeling all-electrical detection of the inverse Edelstein effect by spin-polarized tunneling in a topological-insulator/ferromagnetic-metal heterostructure, Physical Review B, 97, 144417 (2018). Erratum, Physical Review B, 98, 219908 (2018).
  7. R. Dey, A. Roy, T. Pramanik, A. Rai, S. H. Shin, S. Majumder, L. F. Register, S. K. Banerjee, Detection of current induced spin polarization in epitaxial Bi2Te3 thin film, Applied Physics Letters, 110, 122403 (2017).
  8. T. Pramanik*, A. Roy*, R. Dey*, A. Rai, S. Guchhait, H. C. P. Movva, C.-C. Hsieh, S. K. Banerjee, Angular dependence of magnetization reversal in epitaxial chromium telluride thin films with perpendicular magnetic anisotropy, Journal of Magnetism and Magnetic Materials, 437, 72 (2017). [*equal contributions]
  9. B. Ghosh, R. Dey, L. F. Register, S. K. Banerjee, A simulation study of voltage-assisted low-energy switching of a perpendicular anisotropy ferromagnet on a topological insulator, Journal of Computational Electronics, 16, 120 (2017).
  10. A. Roy, R. Ghosh, A. Rai, A. Sanne, K. Kim, H. C. P. Movva, R. Dey, T. Pramanik, S. Chowdhury, E. Tutuc, S. K. Banerjee, Intra-domain periodic defects in monolayer MoS2, Applied Physics Letters, 110, 201905 (2017).
  11. R. Dey, A. Roy, T. Pramanik, S. Guchhait, S. Sonde, A. Rai, L. F. Register, S. K. Banerjee, Localization and interaction effects of epitaxial Bi2Se3 bulk states in two-dimensional limit, Journal of Applied Physics, 120, 164301 (2016).
  12. B. Ghosh, R. Dey, L. F. Register, S. K. Banerjee, Voltage-controlled low-energy switching of nanomagnets through Ruderman-Kittel-Kasuya-Yosida interactions for magnetoelectric device applications, Journal of Applied Physics, 120, 034303 (2016).
  13. S. Majumder, S. Guchhait, R. Dey, L. F. Register, S. K. Banerjee, Large Magnetoresistance at Room Temperature in Ferromagnet/Topological Insulator Contacts, IEEE Transactions on Nanotechnology, 15, 671 (2016).
  14. A. Roy, H. C. P. Movva, B. Satpati, K. Kim, R. Dey, A. Rai, T. Pramanik, S. Guchhait, E. Tutuc, S. K. Banerjee, Structural and electrical properties of MoTe2 and MoSe2 grown by molecular beam epitaxy, ACS Applied Materials & Interfaces, 8, 7396 (2016).
  15. U. Roy, R. Dey, T. Pramanik, B. Ghosh, L. F. Register, S. K. Banerjee, Magnetization switching of a metallic nanomagnet via current-induced surface spin-polarization of an underlying topological insulator, Journal of Applied Physics, 117, 163906 (2015).
  16. A. Roy, S. Guchhait, R. Dey, T. Pramanik, C.-C. Hsieh, A. Rai, S. K. Banerjee, Perpendicular magnetic anisotropy and spin glass-like behavior in molecular beam epitaxy grown chromium telluride thin films, ACS Nano, 9, 3772 (2015).
  17. A. Rai, A. Valsaraj, H. C. P. Movva, A. Roy, R. Ghosh, S. Sonde, S. Kang, J. Chang, T. Trivedi, R. Dey, S. Guchhait, S. Larentis, L. F. Register, E. Tutuc, S. K. Banerjee, Air stable doping and intrinsic mobility enhancement in monolayer molybdenum disulfide by amorphous titanium suboxide encapsulation, Nano Letters, 15, 4329 (2015).
  18. R. Dey, T. Pramanik, A. Roy, A. Rai, S. Guchhait, S. Sonde, H.C.P. Movva, L. Colombo, L. F. Register, S. K. Banerjee, Strong spin-orbit coupling and Zeeman spin splitting in angle dependent magnetoresistance of Bi2Te3, Applied Physics Letters, 104, 223111 (2014).
  19. A. Roy, S. Guchhait, S. Sonde, R. Dey, T. Pramanik, A. Rai, H. C. P. Movva, L. Colombo, S. K. Banerjee, Two-dimensional weak anti-localization in Bi2Te3 thin film grown on Si(111)-(7x7) surface by molecular beam epitaxy, Applied Physics Letters, 102, 163118 (2013).

Patents:

Conferences:

  1. A. Roy, T. Pramanik, R. Dey, A. Rai, S. Banerjee, Epitaxial Growth and Characterization of Chromium Selenide Thin-Films on c-Al2O3(0001), Electronics Materials Conference 2019.
  2. S. Mozaffari, R. Dey, D. Morin, G. Ponti, J. Markert, Multiband Conduction at the PrAlO3/SrTiO3 Interface, American Physical Society (APS) March Meeting 2018.
  3. U. Roy, R. Dey, T. Pramanik, B. Ghosh, L. F. Register, S. K. Banerjee, Magnetization switching of a nanomagnet by spin polarized surface states of a topological insulator, APS March Meeting, 2015.
  4. R. Dey, A. Roy, T. Pramanik, S. Guchhait, S. Sonde, A. Rai, S. Majumder, B. Ghosh, L. F. Register, S. K. Banerjee, Low temperature magnetoresistance studies in MBE grown topological insulator thin films, APS March Meeting 2015.
  5. B. Ghosh, T. Pramanik, R. Dey, U. Roy, L. F. Register, S. K. Banerjee, Ultra Low Energy Switching of Ferromagnet with Perpendicular Anisotropy on Topological Insulator by Voltage Controlled Magnetic Anisotropy, APS March Meeting 2015.
  6. A. Roy, S. Guchhait, R. Dey, T. Pramanik, C.-C. Hsieh, A. Rai, S. K. Banerjee, Magnetic and magneto-transport studies of MBE grown Cr2Te3 thin films with perpendicular magnetic anisotropy, APS March Meeting 2015.
  7. R. Dey, T. Pramanik, A. Roy, A. Rai, S. Guchhait, S. Sonde, H.C.P. Movva, L. Colombo, L. F. Register, S. K. Banerjee, Evidence of Strong Spin-Orbit Coupling & Effects of Zeeman Spin Splitting in Angle-Dependent Anisotropic Magnetoresistance of Topological Insulator Bi2Te3 Thin Film, International Conference on the Physics of Semiconductors (ICPS) 2014.

Undergraduate Courses:

Role Course Title Year
Tutor ESC 201: Introduction to Electronics 2022-23 Semester I
Instructor EE210A: Microelectronics I 2021-22 Summer Semester
Tutor EE210A: Microelectronics I 2021-22 Semester II
Tutor EE370A: Digital Electronics 2021-22 Semester I
Tutor ESC 201: Introduction to Electronics 2020-21 Semester II
Tutor ESC 201: Introduction to Electronics 2020-21 Semester I

Postgraduate Courses:

Role Course Title Year
Instructor EE616A: Semiconductor Device Modelling 2022-23 Semester I
Instructor EE619A: VLSI System Design 2021-22 Semester II
Instructor EE614A: Solid State Devices I 2021-22 Semester I
Instructor EE698T: Charge and Heat Transport in Semiconductors 2020-21 Semester II

Continuing Education Courses:

Role Program Course Title Date
Organizer, Instructor ATAL Academy Faculty Development Program Physics of Nanoelectronics 02-06 August, 2021
Organizer, Instructor Quality Improvement Program IIT Kanpur Transport in Nanoelectronics 15-20 March, 2021

Online Resources:

Experience:

Position Year Institution
Assistant Professor 2020 - Present Indian Institute of Technology Kanpur
Post-Doctoral Fellow 2019 - 2020 The University of Texas at Austin
Graduate Research Assistant 2012 - 2019 The University of Texas at Austin
Globalink Research Internship 2011 Summer The University of Toronto
SURGE Internship 2010 Summer Indian Institute of Technology Kanpur

Education:

Degree Year Institution
PhD (ECE) 2019 The University of Texas at Austin
M.S.E. (ECE) 2014 The University of Texas at Austin
B.Tech. (EE) 2012 Indian Institute of Technology Kanpur
Higher Secondary 2008 Burdwan Municipal High School
Secondary 2006 Burdwan Municipal High School

Awards and Scholarships:

Contact Information

Dr. Rik Dey
Assistant Professor

Office Address:
Western Labs (WL), Room no: WL-121
Department of Electrical Engineering
Indian Institute of Technology Kanpur
Kanpur, UP, India 208016

Office Phone: 512-259-2187
Email id: rikdey@iitk.ac.in

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