Rajib Sarkar

© Sarkar

Senior Scientist

Born: 1979, West Bengal, India

 PhD in Physics-2009, Jadavpur University, India (work done at SINP)

Contact

Physikgebäude Zellescher Weg 16
D-Flügel, Zimmer D212
Tel.:    +49 351 463-35233
Fax:    +49 351 463-37734
eMail:  Rajib Sarkar

Research interests
Magnetism and Superconductivity

Methods
Nuclear Magnetic Resonance (NMR),  Muon Spin Resonance (MuSR)

Projects:

• Principal Investigator in SFB 1143 “Correlated Magnetism: From Frustration to Topology”  funded by the Deutsche Forschungsgemeinschaft for the period 1/2023 - 12/2026. Project C02 : Competing orders and spin dynamics: Nuclear probes.
• SFB 1143 “Correlated Magnetism: From Frustration to Topology”  funded by the Deutsche Forschungsgemeinschaft for the period 1/2019 - 12/2022. Project C02 : Competing orders and spin dynamics: Nuclear probes.
• Principal Investigator in GRK 1621 “Itinerant magnetism and superconductivity in intermetallic compounds” funded by the the Deutsche Forschungsgemeinschaft for the period (../2015 - 03/2020).
• Principal Investigator in SFB 1143 “Correlated Magnetism: From Frustration to Topology”  funded by the Deutsche Forschungsgemeinschaft for the period 1/2015 - 12/2018. Project C02 : Competing orders and spin dynamics: Nuclear probes.
• Deutsche Forschungsgemeinschaft-(SA 2426/1-1) Post doctoral fellowship (2012-
  2014).

Teaching

• Elective course: Winter semester, 2023 (Magnetism I)

• Invited Lectures Heidelberg University-2023 ''Symmetry Breaking in Condensed Matter: An Experimental Perspectives''

• Elective course: Summer semester, 2023 (Magnetism II)

• Elective course: Summer semester, 2021, 2022 (Symmetry Breaking in Condensed Matter: An Experimental Perspectives)
• Elective course: Winter semester, 2018, 2021, 2022 (Application of Solid State Nuclear Magnetic Resonance (NMR) and Muon Spin Rotation/Relaxation on Strongly Correlated Electron Systems)
• Elective course: Summer semester, 2019 (Application of Solid State Nuclear Magnetic Resonance (NMR) and Muon Spin Rotation/Relaxation on Strongly Correlated Electron Systems )
• Physikalisches Grundpraktikum III-Bachelor Physics (2nd semester-Summer term): 2018 (Electron Spin Resonance experiment- supervisor and initial setting up of this experiment)
• Physikalisches Grundpraktikum III-Bachelor Physics (2nd semester-Summer term): 2014, 2015, 2016 (Experiments Superconductivity I)
• Fortgeschrittenenpraktikum -Bachelor Physics (5th Semester-Winter term): 2014, 2015, 2016, 2017, 2018, 2019, 2022 (Nuclear Magnetic Resonance)
• Advanced NMR experiments for Masters students: 2014, 2015, 2016, 2017,  (Nuclear Magnetic Resonance)

Publications (Research ID ORCID Google Scholar)

• Altermagnet with a metallic touch

  R. Sarkar

  Nature Physics, 1-2 (2025)

• Magnetism in the Kitaev quantum spin liquid candidate RuBr₃ 

  T. Weinhold, C. Wang, F. Seewald, V. Grinenko, Y. Imai, F. Sato, K. Ohgushi, H.-H. Klauss, and R. Sarkar

  Phys. Rev. B 109, 014440 (2024)

• Split superconducting and time-reversal symmetry-breaking transitions, and magnetic order in Sr₂RuO₄   under uniaxial stress

  V. Grinenko, S. Ghosh, R. Sarkar, J.-C. Orain, A. Nikitin, M. Elender, D. Das, Z. Guguchia, F. Brückner, M. E. Barber, J. Park, N. Kikugawa, D. A. Sokolov, J. S. Bobowski, T. Miyoshi, Y. Maeno, A. P. Mackenzie, H. Luetkens, C. W. Hicks, H.-H. Klauss                               Nature Physics 17, 748–754 (2021)   

• Spin Nematic Phase in Iron-Oxychalcogenide Mott Insulators                                            B. Freelon, R. Sarkar, S. Kamusella, F. Brückner, V. Grinenko, Swagata Acharya, Mukul Laad, Luis Craco, Zahra Yamani, Roxana Flacau, Ian Swainson, Yuhao Liu, Hangdong Wang, Jianhua Du, Minghu Fang, H.-H. Klauss                                                                       npj (Nature) Quantum Materials 6, 4 (2021)  arXiv:1708.01693

• Superconductivity with broken time reversal symmetry inside a superconducting s-wave state                                                                                                                                      V. Grinenko, R. Sarkar, K. Kihou, C. H. Lee, I. Morozov, S. Aswartham, B. Büchner, P. Chekhonin, W. Skrotzki, K. Nenkov, R. Hühne, K. Nielsch, D. V. Efremov, S. -L. Drechsler, V. L. Vadimov, M. A. Silaev, P. Volkov, I. Eremin, H. Luetkens, H. H. Klauss            Nature Physics16, 789–794(2020)

• Impact of disorder on dynamics and ordering in the honeycomb lattice iridate      Na₂IrO₃  

  R. Sarkar, Z. Mei, A. Ruiz, G. Lopez, H.-H. Klauss, J. G. Analytis, I. Kimchi, and N. J Curro  Phys. Rev. B 101, 081101 (R) (2020)

• Quantum spin liquid ground state in the disorder free triangular lattice NaYbS₂             R. Sarkar, Ph. Schlender, V. Grinenko, E. Haeussler, Peter J. Baker, Th. Doert, and H.-H. Klauss
  Phys. Rev. B 100, 241116(R) (2019)  

• Magnetic interactions and spin dynamics in the bond-disordered pyrochlore fluoride NaCaCo₂F₇

  J. Zeisner, S. A. Bräuninger, L. Opherden, R. Sarkar, D. I. Gorbunov, J. W. Krizan, T. Herrmannsd örfer, R. J. Cava, J. Wosnitza, B. Büchner, H.-H. Klauss, and V. Kataev  Phys. Rev. B 99, 155104 (2019)

• Dynamic magnetism in the disordered hexagonal double perovskite BaTi_1/2Mn_1/2O₃

  M. R. Cantarino, R. P. Amaral, R. S. Freitas, J. C. R. Araújo, R. Lora-Serrano, H. Luetkens, C. Baines, S. Bräuninger, V. Grinenko, R. Sarkar, H. H. Klauss, E. C. Andrade, and F. A. Garcia

  Phys. Rev. B 99, 054412(2019)

• NaYbS₂ - a new planar spin-1/2 triangular-lattice magnet and putative spin liquid         M. Baenitz, Ph. Schlender, J. Sichelschmidt, Y. A. Onykiienko, Z. Zangeneh, K. M. Ranjith, R. Sarkar, L. Hozoi, H. C. Walker, J. -C. Orain, H. Yasuoka, J. van den Brink, H. H. Klauss, D. S. Inosov, Th. Doert                                                                                                       Phys. Rev. B 98, 220409(R)(2018)

• Anomalous Hall effect in Weyl semimetal half-Heusler compounds RPtBi (R = Gd and Nd)                                                                                                                                      Chandra Shekhar, Nitesh Kumar, V. Grinenko, Sanjay Singh, R. Sarkar, H. Luetkens, Shu-Chun Wu, Yang Zhang, Alexander C. Komarek, Erik Kampert, Yurii Skourski, Jochen Wosnitza, Walter Schnelle, Alix McCollam, Uli Zeitler, Jürgen Kübler, Binghai Yan, H.-H. Klauss, S. S. P. Parkin, and C. Felser                                                                                Proc. Nat. Acad. Sc. 115, 9140 (2018)                                                         

• Analysis of the crystal electric field parameters of YbNi₄P₂                                               Zita Huesges, Kristin Kliemt, Cornelius Krellner, R. Sarkar,  Hans-Henning Klauss, Christoph Geibel, Martin Rotter, Pavel Novak, J. Kunes, Oliver Stockert                   New J. Phys.20, 073021(2018)

• Magnetism and the phase diagram of MnSb₂O₆

  C. Koo, J. Werner, M. Tzschoppe, M. Abdel-Hafiez, P. K. Biswas, R. Sarkar, H. -H. Klauss, G. V. Raganyan, E. A. Ovchenkov, A. Yu. Nikulin, A. N. Vasiliev, E. A. Zvereva, and R. Klingeler                                                                                                                              Phys. Rev. B 97, 224416(2018)

• Low temperature breakdown of antiferromagnetic quantum critical behavior in FeSe V. Grinenko, R. Sarkar, P. Materne, S Kamusella, A. Yamamshita, Y. Takano, Y. Sun, T. Tamegai, D. V. Efremov, S.-L. Drechsler, J.-C. Orain, T. Goko, R. Scheuermann, H. Luetkens, and H.-H.Klauss                                                                                               Phys. Rev. B 97, 201102(R) (2018)

• Uniaxial strain control of spin-polarization in multicomponent nematic order of BaFe₂As₂

  T. Kissikov, R. Sarkar, M. Lawson, B. T. Bush, E. I. Timmons, M. A. Tanatar, R. Prozorov, S. L. Bud'ko, P. C. Canfield, R. M. Fernandes, and N. J. Curro                                  Nature Communication 9, 1058 (2018)

• Spin freezing in the disordered pyrochlore magnet NaCaCo₂F₇: NMR studies and Monte-Carlo simulations                                                                                                                      R. Sarkar, J. W. Krizan, F. Brckner, E. C. Andrade, S. Rachel, M. Vojta, R. J. Cava, and H.-H. Klauss                                                                                                                             Phys. Rev. B96, 235117(2017)

• Local nematic susceptibility in stressed BaFe2As2 from NMR electric field gradient measurements

  T. Kissikov, R. Sarkar, M. Lawson, B. T. Bush, E. I. Timmons, M. A. Tanatar, R. Prozorov, S. L. Bud'ko, P. C. Canfield, R. M. Fernandes, W. F. Goh, W. E. Pickett, N. J. Curro                 Phys. Rev. B 96, 241108(R)(2017)

• Macroscopic phase separation of superconductivity and ferromagnetism in Sr_0.5Ce_0.5FBiS_2-xSe_x revealed by muSR                                                                                   A.M. Nikitin, V. Grinenko, R. Sarkar, J.-C. Orain, M.V. Salis, J. Henke, Y.K. Huang, H.-H. Klauss, A. Amato, A. de Visser                                                                                  Scientific Reports 7, 17370 (2017)

• Diluted paramagnetic impurities in nonmagnetic Ba₂YIrO₆                                                 F. Hammerath, R. Sarkar, S. Kamusella, C. Baines, H.-H. Klauss, T. Dey, A. Maljuk, S. Gaß, A.U.B. Wolter, H.-J. Grafe, S. Wurmehl, and B. Büchner                                           

  Phys. Rev. B 96, 165108(2017)

• Nuclear Magnetic Resonance Probe Head Design for Precision Strain Control
  T. Kissikov, R. Sarkar, B. T. Bush, M. Lawson, P. C. Canfield, and N.J. Curro                  Review of Scientific Instruments 88, 103902 (2017)
• Superconductivity with broken time reversal symmetry in ion irradiated Ba_0.27K_0.73Fe₂As₂ single crystals                                                                                                   V. Grinenko, P. Materne, R. Sarkar, H. Luetkens, K. Kihou, C. H. Lee, S. Akhmadaliev, D. V. Efremov, S.-L. Drechsler, and H.-H.Klauss                                                                 Phys. Rev. B 95, 214511 (2017)
• Magnetic order and spin dynamics across a ferromagnetic quantum critical point: mu SR investigations of YbNi₄(P_1-xAs_x)₂                                                                                            R. Sarkar, J. Spehling, P. Materne, H. Luetkens, C. Baines, M. Brando, C. Krellner,      and H.-H. Klauss                                                                                                                         Phys. Rev. B 95, 121111(R) (2017)
• Non-collinear antiferromagnetism of coupled spins and pseudospins in the double perovskite La₂CuIrO₆                                                                                                        Kaustuv Manna, R. Sarkar, S Fuchs, Y.A. Onykiienko, A.K. Bera, G. Aslan Cansever, S.   Kamusella, A. Maljuk, CGF Blum, L.T. Corredor, AUB Wolter, S. M. Yusuf, M. Frontzek, L. Keller, M. Iakovleva, E. Vavilova, H.-J. Grafe, V. Kataev, H.-H. Klauss, D.S. Inosov, S. Wurmehl, B. Buchner                                                                                                       Phys. Rev. B 94, 144437(2016)
• Microscopic coexistence of superconductivity and magnetism in Ca_1-xNa_xFe₂As₂            P. Materne, S. Kamusela, R. Sarkar, T. Goltz, J. Spehling, H. Maeter, L. Harnagea, S. Wurmehl, B. Buchner, H. Luetkens, C. Timm, and H-H Klauss                                  Phys. Rev. B 92, 134511(2015)
• ¹¹⁹Sn-NMR investigations on superconducting Ca₃Ir₄Sn₁₃: Evidence for multigap superconductivity                                                                                                                         R Sarkar, F. Brückner, M. Günther, Kefeng Wang, C. Petrovic, P.K. Biswas, H. Luetkens, E. Morenzoni, A. Amato, H-H. Klauss                                                                          Physica B: Condensed Matter 479, 51–53(2015)
• Superconducting properties and pseudogap from preformed Cooper pairs in the triclinic (CaFe_1−xPt_xAs)₁₀Pt₃As₈                                                                                                    M. A. Surmach, F. Brückner, S. Kamusella, R. Sarkar, P. Y. Portnichenko, J.T. Park, G. Ghambashidze, H. Luetkens, P. Biswas, W. J. Choi, Y. I. Seo, Y. S. Kwon, H. -H. Klauss, D. S. Inosov                                                                                                                                          Phys. Rev. B 91, 104515(2015)
• Coexistence of 3d-Ferromagnetism and Superconductivity in [(Li_1−xFe_x)OH](Fe_1−yLi_y)Se
  U. Pachmayr, F. Nitsche, H. Luetkens, S. Kamusella, F. Bruckner, R. Sarkar, H.-H. Klauss, and D. Johrendt                                                                                                               Angew. Chem. Int. Ed. 54 ,293 (2015)
•  Multigap superconductivity in locally non-centrosymmetric SrPtAs: An ⁷⁵As nuclear quadrupole resonance investigation.
  F. Brueckner, R. Sarkar, M. Guenther, H. Kuehne, H. Luetkens, T. Neupert, A. P. Reyes, P. L. Kuhns, P. K. Biswas, T. Stürzer, D. Johrendt, H.-H. Klauss                                       Phys. Rev. B 90, 220503(R)(2014)
• Magnetic order and spin dynamics in La₂O₂Fe₂OSe₂ probed by ⁵⁷Fe-Moessbauer, ¹³⁹La-NMR, and muon spin relaxation spectroscopy
  M. Günther, S. Kamusella, R. Sarkar, T. Goltz, H. Luetkens, G. Pascua, S.-H. Do, K.-Y. Choi, H. D. Zhou, H.-H. Klauss                                                                                               Phys. Rev. B 90, 184408(2014)
• Unconventional magnetism in multivalent charge-ordered YbPtGe₂ probed by ¹⁹⁵Pt-NMR- and ¹⁷¹Yb-NMR                                                                                                                   R. Sarkar, R. Gumeniuk, A. Leithe-Jasper, W. Schnelle, Y. Grin, C. Geibel, and M. Baenitz   Phys. Rev. B 88, 201101(R)(2013)
• YbPtGe₂: A multivalent charge-ordered system with an unusual spin pseudogap
  R. Gumeniuk, R. Sarkar,, C. Geibel, W. Schnelle, C. Paulmann, M. Baenitz, A. A. Tsirlin, V. Guritanu, J. Sichelschmidt, Y. Grin, and A. L. Jasper                                                      Phys. Rev. B 86, 235138 (2012)
• ³¹P NMR investigations on the ferromagnetic quantum critical system YbNi₄P₂.
  R. Sarkar, P. Khuntia, C. Krellner, F. Steglich, C. Geibel, and M. Baenitz                           Phys. Rev. B 85, 140409(R)(2012)
• Magnetism and superconductivity in Eu_0.2Sr_0.8(Fe_0.86Co_0.14)₂As₂ probed by ⁷⁵As NMR.
  R. Sarkar, R. Nath, P. Khuntia, H S Jeevan, P Gegenwart and M. Baenitz                         J. Phys.: Condens. Matter 24, 045702(2012)
• Interplay between Fe-3d and Ce-4f magnetism and Kondo interaction in CeFeAs_1-xP_xO probed by ⁷⁵As and ³¹P NMR.
  R. Sarkar, M. Baenitz, A. Jesche, F. Steglich and C. Geibel                                                 J. Phys.: Condens. Matter 24, 135602(2012)
• Interplay between Co-3d and Ce-4f magnetism in CeCoAsO.
  R. Sarkar, A. Jesche, C. Mazumdar, A. Poddar, C. Krellner, M. Baenitz, and C. Geibel, Phys. Rev. B 82, 054423 (2010)
• NMR study of ⁵¹V in quasi-one-dimensional integer spin chain compound SrNi₂V₂O₈.
  B. Pahari, K. Ghoshray, R. Sarkar, B. Bandyopadhyay, and A. Ghoshray                 Phys. Rev. B 73, 012407(2006)
• ⁵¹VNMR study of the quasi-one-dimentional alternating chain compound BaCu₂V₂O₈.
  K.Ghoshray, B. Pahari, B. Bandyopadhyay, R. Sarkar and A. Ghoshray                   Phys. Rev. B 71, 214401 (2005)
• ²⁷Al NMR in grain-aligned ternary intermetallic CeNi₂Al₅: A dense Kondo compound.
  R. Sarkar, K.Ghoshray, B. Bandyopadhyay, and A. Ghoshray                                   Phys. Rev. B 71, 104421 (2005)

Outreach and other academic activities:

নিম্ন তাপমাত্রা: কিছু ভাবনা (Low Temperature: Some thoughts) (Popular Science Book)

চুম্বকত্ব (Magnetism) (Popular Science Book)

অভিবাসী পথিক বিজ্ঞানী (Popular Book)