Dr. Dheeraj Kumar Singh

Assistant Professor

Specialization

Condensed matter theory (correlated electron systems)

Email

dheeraj.kumar@thapar.edu

Specialization

Condensed matter theory (correlated electron systems)

Email

dheeraj.kumar@thapar.edu

Contact No: 7800433024

Work Area

  • Quantum magnetism

  • Unconventional superconductivity

  • Quasiparticle excitations and interferences

  • Ordering phenomena including higher-order multipole ordering such as orbital order

  • Other low-energy collective excitations such as spin-wave excitations

  • Finite temperature spectral and transport properties of ordered and disordered systems.

Description of Research Interests

We are interested in ordering phenomena and low-energy collective excitations in condensed matter with particular interest in superconductivity and magnetism exhibited by strongly correlated systems. Our current focus is on material systems such as iron-based superconductors and high-Tc cuprates.

Biography

 

Academics

  • 2005, B.Sc. with major in physics, Indira Gandhi National Open University, New Delhi, India
  • 2008, M.Sc. in Physics, Indian Institute of Technology Kanpur, India                                               
  • 2012, Ph. D. in Theoretical Physics, Indian Institute of Technology Kanpur, India

Work Experience

  • July 2012 – June 2014, Post-Doctoral Fellow, Asia Pacific Center for Theoretical Physics, South Korea
  • July 2014 – April 2015 Post-Doctoral Fellow, Hanyang University, South Korea
  • May 2015– April 2018, Post-Doctoral Fellow, Harish-Chandra Research Institute, Allahabad, India     
  • June 2018– July 2019, Post-Doctoral Fellow, Pohang University of Science and Technology, South Korea
  • July 2019– till date, Assistant professor, Thapar Institute of Engineering and Technology, India

Research Projects:

  • Seed Money in 2020 (3.60 Lakhs), TIET Patiala
  • Start-up Research Grant in 2020 (16.4 Lakhs), DST-SERB   
  • DST-NSM Research Grant in 2020 (12.3 Lakhs)                                                      

Foreign Visits

  • Visited South Korea as a researcher in 2022 (duration: 19 June – 31 July)
  • Visited South Korea as a researcher in 2023 (duration: 15 July – 5 August)

 

Publications and other Research Outputs (SCI)

              

  1. Harun Al Rashid and Dheeraj Kumar Singh,- “Thermal evolution of the single-particle spectral function in the half-filled Hubbard model and pseudogap”, Phys. Rev. B 107, 125139, (2023)

  2. Shubhajyoti Mohapatra, Dheeraj Kumar Singh and Avinash Singh,-"Spin-orbit coupling and magnetism in Sr2CrO4”,  J. Phys.: Condens. Matter 35, 435601 (2023)

  3. Garima Goyal, Aastha Jain, and Dheeraj Kumar Singh, “"Estimating damping effects using a smartphone.," To appear in “The Physics Teacher”, (2023)

  4. Harun Al Rashid, Garima Goyal, Alireza Akbari, Dheeraj Kumar Singh,- “Temperature dependence of quasiparticle interference in d-wave superconductors”, SciPost Phys. Core 6, 033 (2023)

  5. Garima Goyal and Dheeraj Kumar Singh,-”Semimetallic spin-density wave state in iron pnictides” 2023 J. Phys.: Condens. Matter 35 365501 (2023)

  6. Shubhajyoti Mohapatra, Dheeraj Kumar Singh, Rajyavardhan Ray, Sayandip Ghosh and Avinash Singh- “Spin-orbit coupling, orbitally entangled antiferromagnetic order, and collective spin-orbital excitations in Sr2VO4”, Journal of Physics: Condensed Matter, 3545801 (2023)

  7. Garima Goyal and Dheeraj Kumar Singh- “Hund’s coupling and electronic anisotropy in the spin-density wave state of iron pnictides”, Physica B: Condensed Matter, 644 414223 (2022)

  8. Dheeraj Kumar Singh, Samrat Kadge, Yunkyu Bang, and Pinaki Majumdar, “Fermi arcs and pseudogap phase in a minimal microscopic model of d-wave superconductivity” Phys. Rev. B, 105 54501 (2022)               

  9. Dheeraj Kumar Singh and Yunkyu Bang- “Effect of strain-induced orbital splitting on the  magnetic excitations in undoped cuprates”, Phys. Rev. B, 103 035122 (2021)

  10. Dheeraj Kumar Singh and Yunkyu Bang- “Doping-induced disorder and conductivity anisotropy in the spin density wave state of iron pnictides”, Phys. Rev. B, 101 155101 (2020).                

  11. Dheeraj Kumar Singh, Ara Go, Han-Yong Choi and Yunkyu Bang- “The stability of hole-doped antiferromagnetic state in a two-orbital model”, New J. Phys, 22 063048 (2020).

  12. Dheeraj Kumar Singh, Alireza Akbari, and Pinaki Majumdar, - “Quasi-one Dimensional Nanostructures as Signature of Nematicity in Iron Pnictides and Chalcogenides”, Phys. Rev. B Rapid communication, 98 180506 (2018)          

  13. Dheeraj Kumar Singh and Pinaki Majumdar, - “Conductivity anisotropy in the doped iron pnictides: a consequence of the interplay between orbital-weight redistribution and Fermi-surface reconstruction”, Phys. Rev. B, 98 195130 (2018).

  14. Dheeraj Kumar Singh, - “Quasiparticle interferences in the coexistence phase of iron pnictides based on a five-orbital model”, Journal of Physics and Chemistry of Solids, 112 246 (2018).

  15. Dheeraj Kumar Singh and Pinaki Majumdar, - “Highly anisotropic quasiparticle interference pattern in the spin-density wave state of the iron pnictide”, Phys. Rev. B, 96 235111 (2017).

  16. Dheeraj Kumar Singh, - “Spin-wave excitations in the SDW state of iron pnictides: a comparison between the roles of interaction parameters”, Journal of Applied Physics, 122 073906 (2017).

  17. Dheeraj Kumar Singh, - “Two-orbital model for CeB6Europhys. Lett., 118 47003 (2017).

  18. Dheeraj Kumar Singh, - “Spin-wave excitations in the SDW state of doped iron pnictides”, J. Phys.: Condens. Matter, 29 415601 (2017).

  19. Dheeraj Kumar Singh, - “Role of unequal and anisotropic gap in the robustness of determining sign-changing s-wave superconductivity using quasiparticle interference”, Physics Letters A, 381 2761 (2017).

  20. Dheeraj Kumar Singh and Tetsuya Takimoto, - “Charge Order Induced in an Orbital Density-Wave State, J. Phys. Soc. Jpn., 85 044703 (2016).

  21. Dheeraj Kumar Singh, - “Orbital-lattice coupling and orbital-ordering instability in iron pnictides”, Europhys. Lett., 112 27004 (2015).

  22. Dheeraj Kumar Singh, Ki Hoon Lee, and Tetsuya Takimoto, - “On the origin of CE-type orbital fluctuations in the ferromagnetic metallic bilayer La1.2Sr1.8Mn2O7”, J. Phys. Soc. Jpn., 84  064709 (2015).

  23. Dheeraj Kumar Singh, - “Orbital ordering transition in the single-layer manganites near half doping: a weak-coupling approach”, Eur. Phys. J. B, 88 101 (2015).

  24. Dheeraj Kumar Singh and Avinash Singh, - “Magnon self-energy in the correlated ferromagnetic Kondo lattice model: Spin- charge coupling effects on magnon excitations in manganites”, Phys. Rev. B, 88 144410 (2013).

  25. Avinash Singh and Dheeraj Kumar Singh, - “Onset and melting of local orbital order”, J. Phys.: Condens. Matter, 24 086003 (2012).

  26. Dheeraj Kumar Singh, Bhaskar Kamble, and Avinash Singh, - “Spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites”, J. Phys.: Condens. Matter, 22 396001(2010).

  27. Dheeraj Kumar Singh, Bhaskar Kamble, and Avinash Singh, - “Orbital fluctuations, spin-orbital coupling, and anomalous magnon softening in an orbitally degenerate ferromagnet”, Phys. Rev. B, 81 064430 (2010).

  28. Sudhakar Pandey, Subrat Das, Bhaskar Kamble, Saptarshi Ghosh, Dheeraj Singh, Rajyavardhan Ray, and Avinash Singh, - “Fermionic representation for the ferromagnetic Kondo lattice model: Diagrammatic study of spin-charge coupling effects on magnon excitations”, Phys. Rev. B, 77 134447 (2008).

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