Shiro Sakai Centre de Physique Théorique (CPHT) École Polytechnique 91128 Palaiseau Cedex France Tel.: +33 (0)1 6933 4217 Fax.: +33 (0)1 6933 4949 shiro@cpht.polytechnique.fr

Research Interests

My current reseach interests are in electron correlation problems in solids and development of new numerical tools to address the problems. I am particularly interested in

• effects of Hund's coupling in transition-metal compounds,
• roles of zeros of Green's function and its relevance to high-Tc cuprates,
• schemes bridging first-principles and model calculations.

I am studying these issues by means of multiorbital or cluster extension of the dynamical mean-field theory combined with the exact diagonalization method or quantum Monte Carlo method, and/or the maximum entropy method.

---

List of Publications

• Cluster-size dependence in cellular dynamical mean-field theory,
  S. Sakai, G. Sangiovanni, M. Civelli, Y. Motome, K. Held, and M. Imada,
  Phys. Rev. B 85, 035102 (2012).

• Theory of pseudogap and superconductivity in doped Mott insulators,
  M. Imada, Y. Yamaji, S. Sakai, and Y. Motome,
  Ann. Phys. (Berlin) 523, 629 (2011).

• Doped high-Tc cuprate superconductors elucidated in the light of zeros and poles of the electronic Green's function,
  S. Sakai, Y. Motome, and M. Imada,
  Phys. Rev. B 82, 134505 (2010).

• Dichotomy between Large Local and Small Ordered Magnetic Moments in Iron-Based Superconductors,
  P. Hansmann, R. Arita, A. Toschi, S. Sakai, G. Sangiovanni, and K. Held,
  Phys. Rev. Lett. 104, 197002 (2010).

• Roles of zeros of the Green function in Fermi arc and non-Fermi liquid in the two-dimensional Hubbard model,
  S. Sakai, Y. Motome, and M. Imada,
  Physica B 404, 3183 (2009).

• Evolution of electronic structure of doped Mott insulators - reconstruction of poles and zeros of Green's function,
  S. Sakai, Y. Motome, and M. Imada,
  Phys. Rev. Lett. 102, 056404 (2009).

• Itinerant ferromagnetism in the multiorbital Hubbard model: a dynamical mean-field study,
  S. Sakai, R. Arita, and H. Aoki,
  Phys. Rev. Lett. 99, 216402 (2007).

• Quantum Monte Carlo study for multiorbital systems with preserved spin and orbital rotational symmetries,
  S. Sakai, R. Arita, K. Held, and H. Aoki,
  Phys. Rev. B 74, 155102 (2006).

• Application of the perturbation series expansion quantum Monte Carlo method to multiorbital systems having Hund's coupling,
  S. Sakai, R. Arita, and H. Aoki,
  Physica B 378-380, 288 (2006).

• Superconductivity in multi-orbital systems: a dynamical mean field + quantum Monte Carlo study,
  S. Sakai, R. Arita, and H. Aoki,
  Physica B 359-361, 554 (2005).

• Numerical algorithm for the double-orbital Hubbard model - Hund-coupled pairing symmetry in the doped case,
  S. Sakai, R. Arita, and H. Aoki,
  Phys. Rev. B 70, 172504 (2004).

---

Curriculum Vitae

• 10/2011 - present: Postdoctoral fellow in the group of Prof. Antoine Georges at École Polytechnique, France.

• 10/2009 - 9/2011: Postdoctoral fellow in the group of Prof. Karsten Held at Vienna University of Technology, Austria.

• 4/2007 - 9/2009: Postdoctoral fellow in the group of Prof. Masatoshi Imada at University of Tokyo, Japan.

• 3/2007: Ph. D in Physics from University of Tokyo.
  Thesis: Theoretical study of Multi-orbital correlated electron systems with Hund's coupling (Supervisor: Prof. Hideo Aoki)

• 4/2004 - 3/2007: Ph.D student in the group of Prof. Hideo Aoki at University of Tokyo, Japan.

• 4/2002 - 3/2004: Master-course student in the group of Prof. Hideo Aoki at University of Tokyo, Japan.

• 4/1998 - 3/2002: Undergraduate student at Kyoto University, Japan.

---

Awards, Grants

• 3/2007: Prize for Ph. D thesis from Faculty of Science, University of Tokyo.
• 4/2010 - 1/2012: Research Fellowship for Young Scientists from Japan Society for the Promotion of Science.

---

Last update xx/xx/2011, Paris, France