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Dr. D. Victor Suvisesha Muthu
  Chief Research Scientist
Department of Physics,
Indian Institute of Science,
Bangalore 560012, INDIA.
email: victor@iisc.ernet.in
phone: 91-80-2293-2857,   
fax: 91-80-2360-2602


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Academic Background:

M.Sc. (Physics) - 1985 Madurai Kamaraj University, Madurai
M.Tech. (Laser Technology) - 1990 Indian Institute of Technology, Kanpur
 Ph.D. (Physics)- 2000 Indian Institute of Science, Bangalore

Post-doctoral fellow :  May 2000 -  August 2001 Department of Physics, University of Missouri, Kansas City, U.S.A.
Visiting Scientist : May 2006 - September 2006  Department of Physics, University of Missouri, Kansas City, U.S.A.
Sabbatical : December 2007 - October 2008 Department of Physics, University of Missouri, Kansas City, U.S.A.

Research Interest  

Raman Spectroscopy



Raman Scattering


             Raman scattering is a powerful probe for characterization and to unravel basic science behind many novel phenomena in physics. It is a contactless method
with high spatial  resolution (~ 1 micron). It is very  sensitive to external and internal perturbations like strain, electric fields, temperature and pressure. We study
systems under low temperature ( up to 4 K ) and at high pressure ( up to 30 GPa). We have studied many interesting systems like carbon and boron nitride
nanotubes, pyrochlores, topological insulators, iron pnictide superconductors using Raman spectroscopy. Most of these studies were carried out in collaboration
with Prof. A.K. Sood’s group.

High Pressure Physics

         High pressure research involves studying the effects of extremely high pressures on materials. To attain pressures of approximately 300,000 to 400,000 atmospheres, 
a device known as the diamond anvil cell is used. A small amount of sample material (typically ~ 100 micron in size) is placed between the tips of two gem quality diamonds
which are mounted in the diamond anvil cell. The diamonds are then pushed together. Due to the small areas (typically ~ 10-7 m2), only nominal forces are needed to achieve
high pressures. We use a number techniques ( Raman scattering and x-ray diffraction ) to study the materials under pressure.



Facilities


1)      Single monochromator based Raman Spectrometer:

 

We have built a micro Raman spectrometer in the lab based on a single monochromator.  It uses a single grating 0.5 m monochromator (Jobin Yvon iHR550 model)
to disperse the light and a notch filter to reject the laser line. The sample is excited with 532 nm laser line using an air cooled diode pumped solid state laser (DPSS).
A 50 X objective is used to focus the laser beam (spot size ~ 3 µm) and also to collect the scattered light. The scattered light from the sample is detected with a back
illuminated CCD. It is a very simple system but the through put is very high so that experiments under ultra high pressure can be carried out.





2)       Diamond anvil cells for high pressure Raman measurements:

 

We have a Mao-Bell type diamond anvil cell which contains two gem quality diamonds facing each other with a flat face of 600 micron. Samples will be placed
 and squeezed in between the diamonds and  pressures up to 30 GPa (3,00,000 atm) can be achieved.

Ruby

Ruby


We have a Merrill-Bassett type diamond anvil cell to do Raman measurement at high pressure and low temperature simultaneously.

 



 Research Project
 
Optical Tweezer based Near Field Raman Spectrometer at High Pressure
2D Materials

Other Activities
    Set up synchrotron based high pressure x-ray diffraction experiment facility at the Indian Beam Line,
    Photon Factory, Japan
Ph.D. Students (thesis awarded) 
    1. Biswanath, Ph.D. (2013)

    2. Pradeep, Ph.D. (2014)

    3. Achintya Bera Ph.D. (2018)

    4. Satyendranath Gupta Ph.D. (2018)

    5. Subhadip Das Ph.D. (2021)
Joint students with Prof. A.K. Sood

    Ph.D. Students (Present)

    1. Anoop Thomas
    2. Sukanya Pal (Submitted)
    3. Srishti Pal (Submitted)
    4. Rosalin
    5. Sebabrata Kisku
    6. Goutam Misra



      List of Publications ( Latest ) :

           


        1.    Satyendra Nath Gupta, Anjali Singh, Sujoy Sarkar, D.V.S. Muthu, Srinivasan Sampath, Umesh Waghmare, and A. K. Sood,
                Pressure-induced electronic and isostructural phase transitions in PdPS: Raman, x-ray, and first-principles study,

          Phy. Rev. B 101, 035123(2020) DOI: 10.1103/PhysRevB.101.035123

         

        2.            Pallavi Malavi, Srishti Pal, D.V.S. Muthu, Subodha Sahoo, S. Karmakar and A.K. Sood,
                 Pressure-induced tuning of quantum spin liquid state in ZnCu 3(OH) 6Cl,

          Phys. Rev. B 101, 214402 (2020) DOI: 10.1103/PhysRevB.101.214402

         

        3.       A. Bera, Anjali Singh, Y.A. Sorb, Ramesh Naidu Jenjeti, D.V.S. Muthu, S. Sampath, Chandrabhas Narayan, U.V. Waghmare and A.K. Sood,
                Chemical ordering and pressure- induced isostructural and electronic transitions in MoSSe crystal,

          Phys. Rev B 102, 014103 (2020) DOI: 10.1103/PhysRevB.102.014103


        4.     Sukanya Pal, Shivani Grover, Luminita Harnagea, Prachi Telang, Anupam Singh, D.V.S. Muthu, U.V. Waghmare and A.K. Sood,
                 Destabilizing Excitonic Insulator Phase by Pressure Tuning of Exciton-Phonon Coupling.

           Physical Review Research 2, 043182 (2020) DOI: 10.1103/PhysRevResearch.2.043182


        5.     Srishti Pal, Pallavi Malavi, Shashank Chaturvedi, Subhadip Das, S. Karmakar, D.V.S. Muthu, Umesh V. Waghmare and A. K. Sood,
                 Tuning the structure of Skyrmion lattice system Cu2OSeO3 under Pressure.

          Phys. Rev B 102, 214107 (2020) DOI: 10.1103/PhysRevB.102.21410


        6.     Manabendra Kuiri, Subhadip Das, D.V.S. Muthu, Anindya Das and A.K. Sood,
                  Thickness dependent transition from 1T’ to Weyl semimetal phase in ultrathin MoTe2: Electrical transport, Noise and Raman studies,

           Nanoscale 12, 8371 (2020) DOI: 10.1039/c9nr10383j


        7.     Pressure-induced phase transitions in the topological crystalline insulator SnTe and its comparison with
                 semiconducting SnSe: Raman and first-principles studies
                Sukanya Pal , Raagya Arora, Subhajit Roychowdhury , Luminita Harnagea , Kumar Saurabh, Sandhya Shenoy , D.V.S. Muthu, 
                        Kanishka Biswas, U. V. Waghmare,  and A. K. Sood , 

          PHYSICAL REVIEW B 101, 155202 (2020) DOI: 10.1103/PhysRevB.101.155202

         

        8.     Subhadip Das, Debnath Koyendrila, Biswanath Chakraborty, Anjali Singh, Shivani Grover, D.Victor.S. Muthu, Umesh Waghmare and A.K. Sood,
                 Symmetry induced phonon renormalization in few layers of 2H-MoTe2 transistors: Raman and first-principles studies.

           Nanotechnology 32, 045202 (2020)https://doi.org/10.1088/1361-6528/abbfd6

         

        9.     Subhadip Das, Suchitra Prasad, Biswanath Chakraborty, Bhakti Jariwala, Sai Shradha, D.V.S. Muthu, Arnab Bhattacharya, U.V. Waghmare and A.K. Sood,
                 Doping controlled Fano resonance in bilayer 1T’-ReS2: Raman experiments and first-principles theoretical analysis.

          Nanoscale 13, 1248-1256 (2021)  DOI: 10.1039/d0nr06583h

         

        10.     Achintya Bera, Anjali Singh, Satyendra Nath Gupta, K Glazyrin, D.V.S. Muthu, U.V. Waghmare and A K Sood,
                 Pressure-induced isostructural electronic topological transitions in 2H-MoTe2: X-ray diffraction and first-principles study.

          J. Phys.: Condens. Matter 33 (2021) 065402 (8pp) https://doi.org/10.1088/1361-648X/abaeac

                      

            11.    Mithun K.P, Srabani Kar, Abinash Kumar, D.V.S. Muthu, N. Ravishankar and A.K. Sood,
              Dirac surface plasmons in Photoexcited Bismuth Telluride nanowires: Optical Pump- Terahertz Probe Spectroscopy.
              Nanoscale DOI: 10.1039/D0NR09087E (2021)

        12. Anoop Thomas,         Kunwar Vikram, D.V.S. Muthu, and A.K. Sood, Structural phase transition from 1H to 1T' at low pressure
              in supported monolayer WS2: Raman study
              Solid State Communications 336, 114412 (2021)

        13.         Walter Schnelle, Beluvalli E. Prasad, Martin Jansen, Claudia Felser, Evgenia Komleva, Sergey V. Streltsov, Igor I. Mazin, Dmitry Khalyavin,
              Pascal Manuel, Sukanya Pal, D.V.S. Muthu, A.K. Sood, Ekaterina S. Klyushina, Bella Lake, Jean-Christophe Orain and Hubertus Luetkens
              Phys. Rev. B 103, 214413 (2021)

        14.         Srishti Pal, Koyendrila Debnath, Satyendra Nath Gupta, Luminita Harnagea, D.V.S. Muthu, Umesh V. Waghmare and A.K. Sood
             Pressure-induced 1T to 3R structural phase transition in metallic VSe2: X-ray diffraction and first-principles theory
             Phys. Rev. B 104, 014108 (2021)

        15. Srishti Pal, Arnab Seth, Piyush Sakrikar, Anzar Ali, Subhro Bhattacharjee, D. V. S. Muthu, Yogesh Singh, and A. K. Sood
             Probing signatures of fractionalization in the candidate quantum spin liquid Cu2IrO3 via anomalous Raman scattering
             Phys. Rev. B 104, 184420 (2021)