Centers & Labs

RIKEN Center for Emergent Matter Science

Emergent Computational Physics Research Unit

Unit Leader: Mohammad Saeed Bahramy (Ph.D.)
Mohammad Saeed Bahramy(Ph.D.)

We focus on the study of exotic states of quantum matter by means of the first-principles methods of computational electronic-structure theory. We are particularly interested in studies of topological phenomena in strongly spin-orbit coupled systems, emergent phenomena at the interface of heterogeneous materials systems, thermopower generation and manipulation in low-dimensional systems, strongly correlated electron systems, and superconductivity. The primary goal of our research is to theoretically predict new physical phenomena in these systems and design materials with advanced electronic and magnetic functionalities. We are also interested in the development of new theoretical approaches and computational techniques to extend the reach and power of the available first-principles methods.

Main Research Field

Interdisciplinary science and engineering

Related Research Fields

Engineering

Keywords

  • Topological quantum phenomena
  • Two-dimensional electron systems
  • Superconductivity
  • Thermoelectricity
  • First-principles calculations

Selected Publications

  1. Bahramy, M. S., Ogawa, N.:
    "Bulk Rashba semiconductors and related quantum phenomena"
    Advanced Materials 29, 1605911 (2017).
  2. Sakano, M., Bahramy, M. S., Tsuji, H., Araya, I., Ikeura, K., Sakai, H., Ishiwata, S., Yaji, K., Kuroda, K., Harasawa, A., Shin, S., Ishizaka, K.:
    "Observation of spin-polarized bands and domain-dependent Fermi arcs in polar Weyl semimetal MoTe2"
    Phys. Rev. B 95, 121101(R) (2017).
  3. Bawden, L., Cooil, S. P., Mazzola, F., Riley, J. M., Collins-McIntyre, L. J., Sunko, V., Hunvik, K. W. B., Leandersson, M., Polley, C. M., Balasubramanian, T., Kim, T. K., Hoesch, M., Wells, J. W., Balakrishnan, G., Bahramy, M. S., King, P. D. C.:
    "Spin-valley locking in the normal state of a transition-metal dichalcogenide superconductor"
    Nature Communications 7, 11711 (2016).
  4. Riley, J. M., Meevasana, W., Bawden, L., Asakawa, M., Takayama, T., Eknapakul, T., Kim, T. K., Hoesch, M., Mo, S-K., Takagi, H., Sasagawa, T., Bahramy, M. S., King, P. D. C.:
    " Negative electronic compressibility and tunable spin splitting in WSe2"
    Nature Nanotechnology 10, 1043 (2015).
  5. Chang, P.-H., Bahramy, M. S., Nagaosa, N., and Nikolic B. K.:
    "Giant thermoelectric effect in graphene-based topological insulators with heavy adatoms and nanopores"
    Nano Letters 14, 3779-3778 (2014).
  6. Murakawa, H., Bahramy, M. S., Tokunaga, M., Kohama, Y., Bell, C., Kaneko, Y., Nagaosa, N., and Tokura, Y.:
    "Detection of Berry's phase in a bulk Rashba semiconductor"
    Science 342, 1490 (2013).
  7. Bahramy, M. S., King, P. D. C., de la Torre, A., Chang, J., Shi, M., Patthey, L., Balakrishnan, G., Hofmann, Ph., Arita, R., Nagaosa, N., and Baumberger, F.:
    "Emergent quantum confinement at topological insulator surfaces"
    Nature Communications 3, 1159 (2012).
  8. Bahramy, M. S., Yang, B. -J., Arita, R., and Nagaosa, N.:
    "Emergence of non-centrosymmetric topological insulating phase in BiTeI under pressure"
    Nature Communications 3, 679 (2012).
  9. Bahramy, M. S., Arita, R., and Nagaosa, N.:
    "Origin of giant bulk Rashba splitting: Application to BiTeI"
    Phys Rev. B. 84, 041202(R) (2011).
  10. Ishizaka, K., Bahramy, M. S., Murakawa, H., Sakano, M., Shimojima, T., Sonobe, T., Koizumi, K., Shin, S., Miyahara, H., Kimura, A., Miyamoto, K., Okuda, T., Namatame, H., Taniguchi, M., Arita, R., Nagaosa, N., Kobayashi, K., Murakami, Y., Kumai, R., Kaneko, Y., Onose, Y., and Tokura, Y.:
    "Giant Rashba-type spin splitting in bulk BiTeI"
    Nature Materials 10, 521 (2011).

Contact information

2-1 Hirosawa,
Wako, Saitama
351-0198, Japan
Tel: +81-(0)48-462-1111
Fax: +81-(0)48-462-4667

Email: bahramy [at] riken.jp