Dr. Saicharan Aswartham

Department:IFF - Magnetic Oxides and Intermetallics
Address:IFW Dresden
Helmholtzstraße 20
01069 Dresden
Telephone number:+49-351-4659-668
E-mail:s.aswartham(at)ifw-dresden.de



Education

Ph.D. in Physics from IFW-Dresden (TU-Dresden), 2012, Germany.

Biography

Jan '16 - Present: Post-doctoral fellow, IFW Dresden, Germany.

Mar '14 - Nov '16: Post-doctoral fellow, University of kentucky, Lexington, USA

Nov '12 - Mar '14: Post-doctoral fellow, IFW Dresden, Germany.

Aug '09 - Nov '12: Ph.D in Physics from IFW-Dresden, Germany.

Feb '09 - Aug '09: Guest scientist in IFW-Dresden, Germany.

Awards/Prize

Young scientist prize from German Crystal Growth Socienty (DGKK) DGKK-Nachwuchsforscherpreises 2014

Invited Talks

International workshop on Fe-based superconductors, 23-25th May’ 2016, IFW-Dresden, Germany.

Summer school on Fe-based superconductors, 4-8th April’ 2016, Strokow, Germany.

German Crystal Growth Society (DGKK) Annual Meeting, 12th Mar’ 2014, Halle,

Germany Trilateral workshop HTSC: Fe-Based Superconductors, Zvenigorod, 1st Oct’ 2013, Moscow/ Russia

Physikalisches Institut University of Stuttgart, 18th Sep’ 2012, Germany

Memberships

German Physical Society (DPG)

German Crystal growth Society (DGKK)

American Physical Society (APS)

Referee

Physical Review Letters (PRL)

Physical Review B (PRB)

Research

Discovery, single crystal growth and characterization of novel quantum materials; superconducting and magnetic materials 

Selected Publications

2016

38) K. Iida, F. Kurth, V. Grinenko, J. Engelmann, M. Langer, P. Pecchio, D. Daghero, R. Gonnelli, R. Hühne, J. Hänisch, S. Aswartham, M. Erbe, I. Mönch, L. Schultz, B. Holzapfel, Stefan-Ludwig Drechsler, Dmitry Efremov, “Hall plot of Ba(Fe1-xCox)2As2 thin films” Scientific. Reports. 6, 28390, (2016).

37) Seunghyun Khim, Saicharan Aswartham, Vadim Grinenko, Dmitry Efremov, Christian G. F. Blum, Frank Steckel, Daniel Gruner, Anja U. B. Wolter, Stefan-Ludwig Drechsler, Christian Heß, Sabine Wurmehl, and Bernd Büchner, "A calorimetric investigation of RbFe2As2 single crystals" Physica Status Solidi B (2016).

36) F. Wasser, S. Wurmehl, S. Aswartham, Y. Sidis, J. T. Park, A. Schneidewind, B. Büchner, and M. Braden; "Spin reorientation transition in Na-doped BaFe2As2 studied by single crystal neutron diffraction" submitted (2016).

35) A. Athauda, C. Hoffman, Y. Ren, S. Aswartham, J. Terzic, G. Cao, X. Zhu, and D. Louca; "Ferro-lattice-distortions and charge fluctuations in superconducting LaO1−xFxBiS2" arXiv:1601.07517 (2016).

34) S. J. Yuan, K. Butrouna, J. Terzic, H. Zheng, S. Aswartham, L. E. DeLong, P. Schlottmann and G. Cao; “Ground state tuning by spin-orbit and lattice degrees of freedom in hexagonal BaIr1-xRuxO3“ Phys. Rev. B. 93. 165136 (2016)

2015

33) J. C. Wang, S. Aswartham, F. Ye, J. Terzic, H. Zheng, D. Haskel, S. Chikara, Y. Choi, P. Schlottmann, S. J. Yuan, and G. Cao; “Decoupling of the Antiferromagnetic and Insulating States in Tb doped Sr2IrO4“ Phys. Rev. B. 92. 214411 (2015)

32) S. J. Yuan, S. Aswartham, J. Terzic, H. Zheng, H. D. Zhao, P. Schlottmann and G. Cao; “From Jeff=1/2 state to p-wave superconductor in single-crystal Sr2Ir1-xRuxO4“ Phys. Rev. B. 92. 245103 (2015)

31) Evolution of magnetism in single-crystal Ca2Ru1-xIrxO4: S. J. Yuan, J. Terzic, J. C. Wang, L. Li, S. Aswartham, Feng. Ye, W. H. Song, and G. Cao. Phys. Rev. B. 92, 024425, (2015).

30) Charge-order dictated magnetic order in dimer chain Iridate Ba5AlIr2O11: J. Terzic, J. C. Wang, Feng. Ye, W. H. Song, S. J. Yuan, S. Aswartham, R. K. Kaul, L. E. Delong and G. Cao. Phys. Rev. B. 91, 235147, (2015).

29) Crystal growth and electronic phase diagram of 4d doped Na1-xFe1-xRhxAs in comparision with 3d Na1-xFe1-xCoxAs: F. Steckel, M. Maroslova, R. Beck, I. Morozov, S. Aswartham, D.V. Evtushinsky, Christian. G-F Blum, M. Abdel-Hafiez, D. Bomber, J. Maletz, S. Borisenko, Andrei V. Shevelkov, A.U.B. Wolter-Giraud, C. Hess, S. Wurmehl, and B. Büchner. Phys. Rev. B 91, 184516, (2015).

28) Spin reorientation in Ba0.65Na0.35Fe2As2: stuided by single-crystal neutron diffraction: F. Wasser, A. Schneidewind, Y. Sidis, S. Wurmehl, S. Aswartham, B. Büchner, and M. Braden. Phys. Rev. B 91, 060505(R) (2015)

2014

27) Lattice-tuned magnetism of Ru4+(4d4) ions in single crystals of the layered honeycomb ruthenates Li2RuO3 and Na2RuO3: J. C. Wang, J. Terzic, T. F. Qi, Feng. Ye, S. J. Yuan, S. Aswartham, S. V. Streltsov, D. I. Khomskii, R. K. Kaul. and G. Cao. Phys. Rev. B. 90, 161110(R), (2014).

26) Identical spin fluctuations in Cu and Co doped BaFe2As2 independent of electron doping: H.-J. Grafe, U. Graefe, A. P. Dioguardi, N. J. Curro, S. Aswartham, S. Wurmehl, B. Büchner. Phys. Rev. B. 90, 094519, (2014).

25) Josephson effect and Andreev reflection in Ba1-xNaxFe2As2 (x= 0.25 and 0.35) point contacts: V. V. Fisun, O. P. Balkashin, O.E. Kvitnitskaya, I. A. Korovkin, N. V. Gamayunova, S. Aswartham, S. Wurmehl, Yu. G. Naidyuk. Fizika Nizkikh Temperatur. 40, 1175, (2014).

24) Superconducting properties of K1-xNaxFe2As2 under pressure: V. Grinenko, W. Schottenhamel, A.U.B. Wolter, D. V. Efremov, S.-L. Drechsler, S. Aswartham, M. Kumar, S. Wurmehl, M. Maroslova, I. Morozov, B. Holzapfel, B. Büchner, E. Ahrens, S. I. Troyanov, S. Koehler, E. Gati, S. Knoener, N. H. Hoang, M. Lang, F. Ricci, G. Profeta. Phys. Rev. B. 90, 094511, (2014).

23) Single 20mev boson mobe in KFe2As2 detected by point contact spectroscopy: Yu. G. Naidyuk, O.E. Kvitnitskaya, N. V. Gamayunova, L. Boeri, S. Aswartham, S. Wurmehl, B. Büchner, D. V. Efremov, G. Fuchs, S.-L. Drechsler. Phys. Rev. B. 90, 094505, (2014).

22) Specific Heat of K1-xNaxFe2As2 at very low temperatures: A. Reifenberger, M. Hempel, P. Vogt, S. Aswartham, M. Abdel-Hafiez, V. Grinenko, S. Wurmehl, S.-L. Drechsler, A. Fleischmann, C. Enss, R. Klingeler. Jorurnal of Low Temperature Physics, 175, 5-6, (2014).

21) Exploring point contact spectra of Ba1-xNaxFe2As2 in normal and superconducting states: Yu. G. Naidyuk, O.E. Kvitnitskaya, S. Aswartham, S. Wurmehl, G. Fuchs, K. Nenkov, B. Büchner. Phys. Rev. B. 89, 140512, (2014).

20) Strong pairing at iron 3dxz;yz orbital’s in hole-doped BaFe2As2: D. V. Evtushinsky, V. B. Zabolotnyy, T. K. Kim, A. A. Kordyuk, A. N. Yaresko, J. Maletz, S. Aswartham, S. Wurmehl, A. V. Boris, D. L. Sun, C. T. Lin, H. Q. Luo, Z. S. Wang, H. H. Wen, A. Varykhalov, R. Follath, B. Büchner, and S. V. Borisenko. Phys. Rev. B. 89, 060514, (2014).

19) Superconducting specific heat jump ΔC αTcβ (β=2) K1-xNaxFe2As2 : V. Grinenko, S.-L. Drechsler, D. Efremov, S. Aswartham, D. Gruner, M. Maroslova, I. Morozov, K. Nenkov, A.U.B. Wolter-Giraud, S. Wurmehl, B. Holzapfel, and B. Büchner. Phys. Rev. B. 89, 060504(R), (2014).

2013

18) Diversity of microstructural phenomena in superconducting and non-superconducting RbxFe2-ySe2: A TEM study at the atomic scale: Maria V. Roslova, Oleg I. Lebedev, Igor V. Morozov, Saicharan Aswartham, Andrei V. Shevelkov, Sabine Wurmehl, and Bernd Büchner. Inorganic Chemistry. (2013).

17) Evidence for a vortex-glass transition in superconducting Ba(Fe0.9Co0.1)2As2: G. Prando, R. Giraud, S. Aswartham, M. Abdel-Hafiez, A. U. B. Wolter, S. Wurmehl, and B. Büchner. J. Phys. Condens. Matter, 25, 505701, (2013)

16) Flux dynamics and avalanches in 122 pnictide superconductor Ba0.65Na0.35Fe2Assingle crystals: A. K. Pramanik, S. Aswartham, A. U. B. Wolter, S. Wurmehl, V. Kataev, and B. Büchner. J. Phys. Condens. Matter, 25, 495701 (2013)

15) Evidence of d-wave superconductivity in K1-xNaxFe2As2 (x = 0 and 0.1) single crystals from Low-T Specific Heat: M. Abdel-Hafiez, S. Aswartham, V. Grinenko, I. Morozov, M. Maroslova, O. Vakaliuk, S.-L. Drechsler, S. Johnston , C. Hess, S. Wurmehl, A.U.B. Wolter, B. Büchner, E. L. Green, J. Wosnitza, P. Vogt, A. Reifenberger, and R. Klingeler. Phys. Rev. B. 87, 180507(R), (2013)

14) Observation of charge accumulation and onsite Coulomb repulsion at transition metal impurities in the iron pnictides: R. Kraus, V. Bisogni, L. Harnagea, S. Aswartham, S. Wurmehl, B. Büchner, and J. Geck G. Levy, I. Elfimov, and G.A. Sawatzky. Phys. Rev. B. 87, 134516, (2013)

13) Intrinsic pinning and the critical current scaling of clean epitaxial Fe(Se,Te) thin films: K. Iida, J. Hänisch, E. Reich, F. Kurth, R. Hühne, L. Schultz, B. Holzapfel, A. Ichinose, M. Hanawa, I. Tsukada, M. Schulze, S. Aswartham, S. Wurmehl, and B. Büchner. Phys. Rev. B.87, 104510, (2013)

12) Electronic band structure and momentum dependence of the superconducting gap in (Ca, Na)Fe2As2 from angle-resolved photoemission spectroscopy: D. V. Evtushinsky, V. B. Zabolotnyy, L. Harnagea, A. N. Yaresko, S. Thirupathaiah, A. A. Kordyuk, J. Maletz, S. Aswartham, S. Wurmehl, E. Rienks, R. Follath, B. Büchner, S. V. Borisenko. Phys. Rev. B. 87, 094501, (2013)

2012

11) Strong Competetion of Superconducting and Magnetic Order Paramenter in Ba1-xNaxFe2As2 : Hemke Maeter, Gwendolyne Pascua, Hubertus Luetkens, Johannes Knolle, Saicharan Aswartham, Sabine Wurmehl, Günter Behr, Bernd Büchner, Zurab Shermadini, Kamil Sedlak, Alex Amato, Roderich Moessner, Ilya Eremin, Hans-Henning Klauss. arXiv:1210.6881, (2012)

10) Hole-doping in BaFe2As2: The case of Ba1-xNaxFe2As2 single crystals: S. Aswartham, M. Abdel-Hafiez, M. Kumar, G. Behr, D. Bombor, V. B. Zabolotnyy, A. A. Kordyuk, T. K. Kim, D. V. Evtushinsky, S. V. Borisenko, C. Hess, A.U.B. Wolter , S. Wurmehl and B. Büchner. Phys. Rev. B. 85, 224520, (2012)

9) Local magnetic anisotropy in BaFe2As2: A polarized inelastic neutron scattering study: N. Qureshi, P. Steffens, S. Wurmehl, S. Aswartham, B. Büchner, and M. Braden. Phys. Rev. B 86, 060410(R) (2012)

8) Specific heat and upper critical fields in KFe2As2 single crystals: M. Abdel-Hafiez, S. Aswartham, S. Wurmehl, V. Grinenko, C. Hess, S.-L. Drechsler, S. Johnston, A.U.B. Wolter, B. Büchner, H. Rosner, L. Boeri. Phys. Rev. B 85, 134533 (2012)

7) 75As NMR-NQR study in superconducting LiFeAs: S.-H. Baek, H.-J. Grafe, F. Hammerath, M. Fuchs, C. Rudisch, L. Harnagea, S. Aswartham, S. Wurmehl, J. van den Brink, B. Büchner. Europ. Phys. J. B 85 159 (2012)

6) Disordered magnetism in KFe2As2 single crystals: V. Grinenko, S.-L. Drechsler, M. Abdel-Hafiez, S. Aswartham, A.U.B. Wolter-Giraud, S. Wurmehl, C. Hess, K. Nenkov, G. Fuchs, D. Efremov, B. Holzapfel, J. Van den Brink and B. Büchner. Phys. Stat. Sol. (b), pssc.201200805.R1 (2012)

2011

5) Single crystal growth and physical properties of superconducting ferro-pnictides Ba(Fe,Co)2As2 grown using self-flux and Bridgman techniques: S. Aswartham, C. Nacke, G. Friemel, N. Leps, S. Wurmehl, N. Wizent, C. Hess, R. Klingeler, G. Behr, S. Singh, B. Büchner. J. Cryst. Growth 314 341 (2011)

4) Multigap superconductivity in single crystals of Ba0.65Na0.35Fe2As2: A calorimetric investigation A.K. Pramanik, M. Abdel-Hafiez, S. Aswartham, A.U.B. Wolter, S. Wurmehl, V. Kataev,B. Büchner. Phys. Rev. B, 84 64525 (2011)

3) Suppressed superconductivity in charge-doped Li(Fe1-xCox)As single crystals: S. Aswartham, G. Behr, L. Harnagea, D. Bombor, A. Bachmann, I.V. Morozov,V.B. Zabolotnyy, A.A. Kordyuk, T.K. Kim, D.V. Evtushinsky, S.V. Borisenko, A.U.B. Wolter, C. Hess, S. Wurmehl, B. Büchner. Phys. Rev. B 84 54534 (2011)

2) Generic Fe buffer layers for Fe-based superconductors: Epitaxial FeSe1-xTex thin films: K. Iida, J. Haenisch, M. Schulze, S. Aswartham, S. Wurmehl, B. Büchner, L. Schultz, B. Holzapfel. Appl. Phys. Lett. 99 202503 (2011) 2010

1) Critical current and vortex dynamics in single crystals of Ca(Fe1-xCox)2As2 A.K. Pramanik, L. Harnagea, S. Singh, S. Aswartham, G. Behr, S. Wurmehl, C. Hess, R. Klingeler, B. Büchner. Phys. Rev. B 82 14503 (2010)