Academics and Past Experience:

  Bachelors: IIT Kanpur
  MS: Purdue Univ.
  PhD in Condensed matter Physics - Purdue Univ.
  Post Doctor at Max Planck Institute (Stuttgart)
  Postdoc at NTT Basic Research labs (Japan)
  Asst. Prof. at  IIT Delhi
  Visiting Scientist at Texas Center for Superconductivity, Univ. of Houston
  Visiting Fellow at Cavendish Lab, Univ. of Cambridge

Special awards, honors, or distinctions:

 Fellowship at the Cavendish Lab (Univ. of Cambridge)
 Our (Prof. B. Chakrabarti's and mine) joint proposal for Applied Mathematics and Computational Science
 Center at SINP was selected and funded, after screening at IMSc (Chennai) and BARC (Mumbai) in 2004.
 David Ross Fellowship at Purdue Univ.
 Certificates of merit at IIT Kanpur
 State Special Merit Scholarship for several years
 National Science Talent Scholarship in Mathematics

Teaching Experience:
Taught  advanced courses in Condensed Matter Physics,
Many-body Physics, field theoretic methods in Condensed Matter Physics,
Magnetism, Fermi Liquid theory, etc. Also taught a course in Modern
Physics to undergraduates.

Reseach Highlights:

We derived a quasiparticle pseudo Hamiltonian of an infinitesimally polarized electron gas
which fully takes into account the many-body effects of both charge and spin density
 fluctuations. We calculated self-consistently Fermi liquid parameters like the effective
 mass, the effective g-factor, spin susceptibility in two-dimensional systems and found
 reasonable agreement with experiments. My works on electron gas [see especially PRB 38  
10966 (1988); PRB  40 5432, (1990); PRB  49 7887 (1994);  PRB  49 14188 (1994)] are
 well recognized and distinguished scientists (including Nobel prize winners) cite these works.
 In fact G. F. Giuliani and G. Vignale  have written a book ["Quantum Theory of the  
 Electron  Liquid" (Cambridge)]  in which my work forms a major theme of the chapter
"The normal Fermi liquid" (Ch. 8).

      I  had  predicted a novel magnetization instability in the quantum Hall effect regime
 [PRB  44 13101 (1991)] and the proposed experiment (measuring diagonal resistivity
in GaInAs-InP heterostructures)  was carried out by K. von Klitzing  et al. [Phys. Rev. B
  47 4048 (1993)] and the instability  was explicitly demonstrated.  The prediction was also
verified by Mike Pepper  et al. [PRL  79, 4449, (1997)] through activation transport studies.
Several Nobel prize winners  (such as H. L. Stormer, D. C. Tsui, K. v. Klitzing,  and
H.  Kroemer) and distinguished scientists cite this work.

     My paper on colossal magnetoresistance [Phys. Rev. B,  62 14828 (2000)]
contains some important ideas which may help explain the phenomenon.

     By using novel approaches, we (my student Sanjoy Datta and I) solved the
long-standing problem of analytically obtaining the Peierls instability condition in
the Holstein model [Phys. Rev. B 75, 035124 (2007) and Phys. Rev. B  71, 235118  (2005)]
and  predicted the  phase diagram away from half-filling.

     I proposed a new model  (arXiv:0712.0366) to understand cooperative
Jahn-Teller effect.  The model involves a next-nearest-neighbor hopping
and nearest-neighbor repulsion.  The model predicts a dramatic first-order
transition at a critical interaction strength.

    Recently, we (my student Sanjoy Datta and I)  derived an effective d-dimensional Hamiltonian
 for a system of hard-core-bosons coupled to optical phonons in a lattice. Away from half-filling,
 we show that the presence of next-nearest-neighbor hopping in the effective Hamiltonian leads
 to a striking superfluid-to-supersolid transition (arxiv:0812.1987).

Some Recent Talks:

1) "Quantum phase transition and phase diagram at a general filling in the
    spinless one-dimensional Holstein model" at  the  International seminar
    and workshop - (April 10--May 11, 2007) on the "Strong Correlations
    and Angle-Resolved Photoemission Spectroscopy" at MPI-Dresden, Germany.

2) "Cooperative Electron-phonon Interactions in One Dimension" at the
    Moments and Multiplets in Mott Materials  program (Aug. 13--Dec. 14, 2007)
    at KITP, Santa Barbara, USA.

3) "Cooperative Electron-phonon Interactions in One Dimension" at
     Purdue Univ. (USA), Dec. 7 (2007).

4) "Cooperative Jahn-Teller effect in manganite chains", Oct. 22 (2007) at
    TCM group seminar, Cavendish lab, Univ. of Cambridge (UK).

5) "Cooperative electron-phonon interactions in molecular chains"
    at Imperial College (London, UK), Jan. 15 (2008).

6) "Cooperative Jahn-Teller effect in low-dimensional manganites"
    at Univ. of Leicester (UK), Jan. 23 (2008).

7) "Cooperative electron-phonon interactions in molecular chains"
    at Univ. of Bristol (UK) , Feb. 13 (2008).

8) "Magnetic-oxide nanoelectronics" at workshop on "Challenges
      in nanoelectronics" at Saha Inst. on Nov. 27 (2008).

9)  "Quantum phase transition in an anisotropic next-nearest-neighbor
      Heisenberg model" at  meeting on "Entanglement  in quantum condensed
      matter systems" in  IMSc (Chennai), 1-2 Dec. 2008.
 
10) "Quantum phase transition due to cooperative electron-phonon interaction
        in low-dimensional systems" at "Indian condensed matter workshop"
       organized by ICTS of TIFR, 9-22 Dec. (2008).

11) "Supersolidity in a Bose-Holstein model" at the
        Low Dimensional Electron Systems program  (Jan. 20 -June 12, 2009)
      at KITP, Santa Barbara, USA.

12) "Orbital ordering in undoped manganites via a generalized Peierls  instability'',
       at  the ICTS CONDENSED MATTER PROGRAMME 2009,  5-22 Dec (2009).

Some Recent Publications:

  "Using many-body entanglement for coordinated action in game theory problems",
  Sudhakar Yarlagadda,  Econophysics & Economics of Games, Social Choices and
  Quantitative Techniques (NEW ECONOMIC WINDOWS , Springer 2010).

 "Quantum phase transition in Bose-Holstein model in two dimensions",
   Sanjoy Datta and Sudhakar Yarlagadda, arXiv:0812.1987 

 "Orbital ordering in undoped manganites via a generalized Peierls  instability'',
   S. Yarlagadda, P. B. Littlewood, M. Mitra, R. K. Monu, (arXiv:0808.1174)
   Phys. Rev. B 80, 235123 (2009).

 "Cooperative electron-phonon interaction in molecular chains",
   Sudhakar Yarlagadda, arXiv:0712.0366

   "Phase transition and phase diagram at a general filling in the spinless one-dimensional Holstein Model",
   Sanjoy Datta and Sudhakar Yarlagadda, Phys. Rev. B 75, 035124 (2007).

  ''Many-Polaron Effects in the Holstein Model'',
    Sanjoy Datta, Arnab Das, and Sudhakar Yarlagadda,  Phys. Rev. B, 71 235118  (2005).   

   ''A stochastic trading model of wealth distribution'',
      Sudhakar Yarlagadda and Arnab Das, Proccedings of  the international workshop on
      Econophysics of Wealth Distributions (Springer 2005).

   ''An analytic treatment of the Gibbs-Pareto behavior in wealth distribution'',
      Arnab Das and Sudhakar Yarlagadda,  Physica A, 353  529 (2005)
      (cond-mat/0409329; old version cond-mat/0310343).
 
   " Jahn-Teller polarons and their superconductivity in a molecular conductor",
     R. Ramakumar and Sudhakar Yarlagadda, Phys. Rev. B, 69  104519 (2004). 

   " Holstein polarons, Frohlich coupling  and superconductivity in a molecular conductor",
    R. Ramakumar and Sudhakar Yarlagadda, Phys. Rev. B,  67  214502 (2003).

   "Analytic treatment of a trading market model", Arnab Das and Sudhakar Yarlagadda,
     Physica Scripta T106 39 (2003).

  " Microscopic approach to electron-phonon interaction physics in half-doped manganites",
    Sudhakar Yarlagadda, IJMPB 15  No. 27, 3529 (2001).

   "Mean-field approach to charge, orbital, and spin ordering in manganites",
    Sudhakar Yarlagadda and C. S. Ting, IJMPB 15  2719 (2001).

   "Colossal magnetoresistance using the small polaron picture with finite band width effects",
     Sudhakar Yarlagadda,  Phys. Rev. B, 62  14828 (2000).

   "Mixed charge-spin response functions of an arbitrarily polarized electron gas",
     Sudhakar Yarlagadda,   Solid State Commun.,  116  167 (2000).

    Comment on "Spin dependent hopping and colossal negative magnetoresistance in
    epitaxial NdSrMnO3 films in fields upto 50T",
    Sudhakar Yarlagadda, Phys. Rev. Lett., 84  4017 (2000).

   "Screened interaction and self-energy in an infinitesimally polarized electron gas via
     Kukkonen-Overhauser method",
     Sudhakar Yarlagadda and G. F. Giuliani, Phys. Rev. B, 61  12556 (2000).

 
 Selected Earlier Publications:

``Towards a new picture  of  the fractional quantum Hall effect'',
S. Yarlagadda, Physica B,  223-224, 640 (1996).

 ``Many-body local fields and Fermi liquid  parameters in a quasi-two-dimensional electron liquid'',
 S. Yarlagadda and G. F. Giuliani, Phys. Rev. B. 49, 14188 (1994).

 ``Landau theory of the Fermi liquids and the
 integration-over-the-coupling-constant algorithm'',
 S. Yarlagadda and G. F. Giuliani, Phys. Rev. B.  49, 14172 (1994).

``Quasiparticle pseudo hamiltonian of an infinitesimally polarized Fermi liquid'',
S. Yarlagadda and G. F. Giuliani, Phys. Rev. B. 49, 7887 (1994).

``Fermi liquid theory in the low density two-dimensional Hubbard model'',
 S. Yarlagadda and  S. Kurihara, Phys. Rev. B.  48, 10 567 (1993).

``Negative thermodynamic density of states and charge density wave
  instability in the lowest Landau level'',
 S. Yarlagadda,  Phys. Rev. B  48, 4707 (1993).

``Magnetization instabilities at tilted magnetic fields in the quantum Hall regime'',
 S. Yarlagadda, Phys. Rev. B  44, 13101 (1991).

 ``Nuclear spin relaxation due to a two-dimensional electron gas'',
S. Yarlagadda and R. R. Gerhardts,
Proceedings of the 20th International Conference on the Physics of  Semiconductors, Thessaloniki, Greece,
edited by E.M. Anastassakis and  J.D. Joannopoulos  (World Scientific, Singapore, 1990), p. 993.

``Many-body local fields and quasiparticle renormalization effects in two dimensional electronic systems'',
 S. Yarlagadda and G. F. Giuliani, Surface Science,
 229, 410 (1990).

 ``Spin susceptibility in a two-dimensional electron gas'',
 S. Yarlagadda and G. F. Giuliani, Phys. Rev. B  40, 5432 (1989).

``Exact asymptotic behavior of the charge and spin susceptibilities in an interacting Fermi liquid'',
 S. Yarlagadda and G. F. Giuliani, Phys. Rev. B  39, 3386 (1989).

 ``Quasiparticle energy and interaction in a normal electron liquid'',
 S. Yarlagadda and G. F. Giuliani, Solid State Commun.  69, 677 (1989).

``Many-body effective mass and anomalous  g factor in  inversion layers'',
 S. Yarlagadda and G. F. Giuliani, Phys. Rev. B  38, 10966 (1988).

Books/Journals written/edited:

   One of the editors of proceedings of the International Conference on Strongly Correlated
   Electron  Systems (SCES-Y2k) published in IJMPB 15  Nos. 19&20 (2001).
   
   One of the editors of proceedings of the International  Workshop on  Econophysics of
   Wealth Distributions (Springer 2005).

Current Research Interests:

  Manganite physics (CMR, charge, orbital, and spin ordering, etc.),  Transition metal oxides in general, Hubbard-Holstein model,
  Study of coexisting long-range orders (e.g.,  superconductivity and charge-density-wave), Molecular  superconductivity,
  Econophysics,  Quantum computation  and quantum information,  Many-body  effects in electron  gas, Quantum Hall effect,
  Fermi liquid theory,  and Many-body physics  in general.

Collaborations:

Cavendish Lab, Univ. of Cambridge:
Prof. Peter Littlewood

Purdue Univ.:
Prof. G.F. Giuliani 
Prof. A. W. Overhauser

Texas Center for Superconductivity, Univ. of Houston:
Prof. C.S. Ting

Max Planck Inst., Stuttgart:
Prof. K. von Klitzing

IMSc, Chennai:
Prof. G. Baskaran