Argonne National Laboratory

Ramakanta Chapai

Postdoctoral Appointee

Biography

Ramakanta Chapai is a postdoctoral appointee in the Materials Science division at Argonne National Laboratory. He received his undergraduate degree from Tribhuvan University and his M.S. in Physics from Miami University. Ramakanta received his Ph.D. in Physics from Louisiana State University in 2021, where he explored topological properties of several Transition-Metal Pnictides and Chalcogenides through the study of Shubnikov-de Haas (SdH) and de Haas-van Alphen (dHvA) effects. His Ph.D. dissertation has been recognized with ​“Coates Outstanding Dissertation Award-2022”, Department of Physics & Astronomy, Louisiana State University. His current research at Argonne National Laboratory is focused primarily on exploring the electronic and spin properties of correlated quantum materials including topological semimetals and superconductors. Ramakanta has several years of experience on materials synthesis (including bulk single growth) and characterization under extreme conditions such as low temperature, high magnetic field, and high pressure.  The characterization techniques include measurement of X-ray diffraction, magnetic, thermal and charge-transport properties. 

Selected Publications

  • Magnetic Breakdown and Topology in the Kagome Superconductor CsV3Sb5 under High Magnetic Field. R. Chapai, M. Leroux, V. Oliviero, D. Vignolles, M.  P. Smylie, D. Y. Chung, M. G. Kanatzidis, W.-K. Kwok, J. F. Mitchell, and U. Welp, Physical Review Letters 130, 126401 (2023).
  • Superconducting properties and gap structure of the topological superconductor candidate Ti3Sb. R. Chapai, M. P. Smylie, H. Hebbeker, D. Y. Chung, W.-K. Kwok, J. F. Mitchell, and U. Welp, Physical Review B 107, 104504 (2023) (Editors’ Suggestion).
  • Evidence for unconventional superconductivity and nontrivial topology in PdTe. R. Chapai, P. V. S. Reddy, L. Xing, D. E. Graf, A. Karki, T.-R. Chang, and R. Jin, Nature Scientific Reports 13, 6824 (2023).
  • Coexistence of bulk-nodal and surface-nodeless Cooper pairings in a superconducting Dirac semimetal. X. Yáng, Y. Zhong, S. Mardanya, T. A. Cochran, R. Chapai, A. Mine, J. Zhang, Z.-J. Cheng, J. S. Barriga, O. J. Clark, J.-X. Yin, J. Blawat, G. Cheng, I. Belopolski, T. Nagashima, S. Najafzadeh, S. Gao, N. Yao, A. Bansil, R. Jin, T.-R. Chang, S. Shin, K. Okazaki, and M. Z. Hasan, Physical Review Letters 130, 046402 (2023).
  • Superconducting properties of the spin Hall candidate  Ta3Sb with eight fold degeneracy. R. Chapai, A. Rydh, M. P. Smylie, D. Y. Chung, H. Zhen, A. E. Koshelev, J. E. Pearson, W.-K. Kwok, J. F. Mitchell, and U. Welp, Physical Review B 105, 184510 (2022).
  • Fermi surface topology of Kagome lattice superconductor CsV3Sb5 explored through de Haas -van Alphen oscillations. K. Shrestha, R. Chapai, B. K. Pokharel, D. Mierstchin, T. Nguyen, D. Y. Chung, M. G. Kanatzidis, J. F. Mitchell, U. Welp D. Popovic, D. E. Graf, B. Lorenz, and W.-K. Kwok., Physical Review B 105, 024508 (2022)
  • Quantum oscillations with angular dependence in PdTe2 single crystals. R. Chapai, D. E. Graf, J. F. DiTusa, and R. Jin. Journal of Physics Condensed Matter 33, 035601 (2021).
  • Topological behavior and Zeeman splitting in trigonal PtBi2-x single crystals. L. Xing, R. Chapai, R. Nepal, and R. Jin.  Nature Partner Journals Quantum Materials 5, 10 (2020).
  • Evidence for topological semimetallicity in a chain compound TaSe3. A. U. Saleheen, R. Chapai, L. Xing, R. Nepal, D. Gong, X. Gui, W. Xie, D. P. Young, E.W. Plummer, R. Jin. Nature Partner Journals Quantum Materials 5, 53 (2020).
  • Observation of sixfold degenerate fermions in PdSb2. X. Yáng, T. A. Cochran, R. Chapai, D. Tristant, J-X. Yin, I. Belopolski, Z. Chéng, D. Multer, S. S. Zhang, N. Shumiya, M. Litskevich, Y. Jiang, G. Chang, Q. Zhang, I. Vekhter, W. A. Shelton, R. Jin, S.-Y. Xu, and M. Z. Hasan. Physical Review B 101, 201105(R) (2020) (Rapid Communications).
  • Fermions and bosons in nonsymmorphic PdSb2 with sixfold degeneracy. R. Chapai, Y. Jia, W. A. Shelton, R. Nepal, M. Saghayezhian, J. F. DiTusa, E. W. Plummer, C. Jin, and R. Jin. Physical Review B 99, 161110(R) (2019) (Rapid Communications).
  • Magnetism and associated exchange bias in Ni2-xCoxMn1.4Ga0.6. R. Chapai and M. Khan. Journal of Magnetism and Magnetic Materials 403, 97 (2016).
  • Exchange bias phenomena in Ni2-xMn1.4+xGa0.6. M. Khan and R. Chapai. Journal of Alloys and Compounds 647, 935 (2015).