RESEARCH

Currently I am working under Prof. Jainendra Jain on physics of low dimensional systems in particular on fractional quantum Hall effect related stuff.  

 

 

Research Interests

·    Condensed Matter Physics: Physics of low dimensional systems in particular fractional quantum Hall systems, Strongly correlated electron systems, Superfluids, BECs in optical lattices.  

 

·    Demography: Population dynamics and economic development.

 

Published papers

·    Phase diagram for bilayer quantum Hall effect at total filling = 5, Chuntai Shi, Shivakumar Jolad, Nicolas Regnault, and Jainendra K. Jain (2008), (to be submitted to Phys Rev B).

 

·    Electron Operator at the edge of 1/3 fractional quantum Hall liquid, Shivakumar Jolad, Chia-Chen Chang and Jainendra Jain, Phys. Rev. B 75, 165306 (2007), http://arxiv.org/abs/0707.0012v1.

·    Supersolid 4He has nearly isotropic superflow, Wayne M Saslow and Shivakumar Jolad, Phys. Rev. B 73, 092505 (2006), http://arxiv:cond-mat/0511214v1.

 

Conference Presentation and Posters

·    Testing Wens Bosonization conjecture on quantum Hall edge, APS March meeting, Denver, CO, March 2007.

·     Supersolid 4He has nearly isotropic superflow, Wayne M Saslow and Shivakumar Jolad, Poster presentation, APS- March meeting, Baltimore, MD, March 2006.

·    Superfluidity in Solid 4He, Poster presentation at ICTP- Trieste, Italy during Summer School on Quantum Phase transitions, Jul 2005. 

 

     

      Description of Research Work/Projects

  1. Testing Wen's bosonization conjecture: This study builds upon the work of Palacios and MacDonald (Phys. Rev. Lett., 76, 118 (1996)), wherein they identify the bosonic excitations at the edge of the 1/3 fractional quantum Hall state with certain operators introduced earlier by Stone.  Using a quantum Monte Carlo method, we extend to larger systems containing up to 40 electrons and obtain more accurate thermodynamic limits for various matrix elements for a short range interaction.  The results are in agreement with those of Palacios and MacDonald for small systems, but offer insight into the detailed approach to the thermodynamic limit. We also study excitations using the Coulomb ground state for up to nine electrons to ascertain the effect of interactions on the results. 

  2. Super Solids (with Prof. W.M. Saslow, Texas A&M University): This is related to the recently observed Phenomenon of Superfluidity in Solids (Solid 4He). We investigate the behavior Super-flow in Super-solids (BEC solid). We extend previous calculations of the zero temperature superfluid fraction fs versus localization s/d, from the fcc lattice to the experimentally realized (for solid 4He) hcp and bcc lattices.  As expected, for fcc and bcc lattices the superfluid density tensor is proportional to the unit tensor. To numerical accuracy of three-places (but no more), the hcp superfluid density tensor is proportional to the unit tensor. This implies that a larger spread in data on fs, if measured on pure crystals, is unlikely to be due to crystal orientation. An expected value for the localization gives an fs in reasonable agreement with experiment. The bcc lattice has a similar curve of fs versus s/d, but is generally smaller because the lattice is more dilute. arxiv:cond-mat/0511214v1
  3. Electromagnetically Induced Transparency (EIT): (Carried out at Department of Physics, Indian Institute of science from Aug-Oct 2002). This work was done under the guidance of Dr. Vasant Natarajan. Our experiments were on a novel method to study EIT in Rb atoms at room temperature along with simultaneous elimination of  Doppler broadening.  My work involved deriving the expression for the line width for a strongly driven V-system both in the presence and absence of Doppler shift. This was a continuation of the work of G S Agarawal et al on L type systems. I also analyzed the probe and control spectra of V and L system. The results were compared with theoretical predictions. This gave a deeper understanding of the atomic coherence phenomenon. European Physical Journal D vol. 28, pp. 317-322 (2004).   
  4. Wavelet Based De-convolution of Astronomical Images: (carried out at Raman Research Institute, Bangalore, under Prof. N Udaya Shankar). The purpose was to study and compare the conventional methods of deconvolution with the Multi-resolution analysis and then implement and test the technique of wavelet-based deconvolution. For this (Multi-Resolution CLEAN) we employed the Wavelet Transform techniques, which are the most efficient basis for analyzing non-stationary signals (here 2D Images). We compared the algorithm developed, with the well-known and established conventional techniques currently employed in Radio Astronomy and later applied our technique to the images made by meter wave - Mauritius Radio Telescope (MRT). Based on our study, we proposed a modified wavelet filter for deconvolving MRT images, which proved to be more efficient than all other techniques. 

 

 

BEC: Bose Einstein Condensate