Strongly-correlated electron systems; High-pressure physics; Heavy-fermion materials; One-dimensional spin systems; Quantum phase transitions; Nuclear magnetic resonance
Shiroka T., Pikulski M., Zhigadlo N. D., Batlogg B., Mesot J., Ott H. R. (2015), Pairing of weakly correlated electrons in the platinum-based centrosymmetric superconductor SrPt3P, in Physical Review B - Condensed Matter and Materials Physics
, 91(24), 245143.
Lamura G., Shiroka T., Bonfà P., Sanna S., De Renzi R., Putti M., Zhigadlo N. D., Katrych S., Khasanov R., Karpinski J. (2015), Slow magnetic fluctuations and superconductivity in fluorine-doped NdFeAsO, in Physical Review B - Condensed Matter and Materials Physics
, 91(2), 024513.
Pikulski M., Shiroka T., Ott H. R., Mesot J. (2014), A firmware-defined digital direct-sampling NMR spectrometer for condensed matter physics, in Review of Scientific Instruments
, 85(9), 093906.
Lamura G., Shiroka T., Bonfà P., Sanna S., De Renzi R., Caglieris F., Cimberle M. R., Iimura S., Hosono H., Putti M. (2014), Crossover between magnetism and superconductivity in LaFeAsO with low H-doping level, in Journal of Physics Condensed Matter
, 26(29), 295701.
Lamura G, Shiroka T, Bonfà P, Sanna S, Bernardini F, De Renzi R, Viennois R, Giannini E, Piriou A, Emery N, Cimberle M R, Putti M (2013), A magnetic glassy phase in Fe(1+y)SexTe(1−x) single crystals, in Journal of Physics: Condensed Matter
, 25(15), 156004-156004.
Shiroka T., Thede M., Wittenfeld L., Litterst F. J., Cahen S., Rida H., Emery N., Marêché J. F., Lagrange P., Hérold C. (2013), Competing magnetic interactions in the graphite-intercalation compound Li0.25Eu1.95C6, in Carbon
, 63, 294-302.
Morenzoni E., Saadaoui H., Amato A., Baines C., Luetkens H., Pomjakushina E., Pikulski M., Shiroka T. (2013), Field dependence of the superconducting gap in YPd2Sn: A μsR and NMR study, in Journal of Physics: Conference Series
, 551(1), 012027.
Casola F., Shiroka T., Feiguin A., Wang S., Grbić M. S., Horvatić M., Krämer S., Mukhopadhyay S., Conder K., Berthier C., Ott H. R., Rønnow H. M., Rüegg Ch, Mesot J. (2013), Field-induced quantum soliton lattice in a frustrated two-leg spin-1/2 ladder, in Physical Review Letters
, 110(18), 187201.
Shiroka T., Casola F., Lorenz W., Prša K., Zheludev A., Ott H. R., Mesot J. (2013), Impact of strong disorder on the static magnetic properties of the spin-chain compound BaCu2SiGeO7, in Physical Review B - Condensed Matter and Materials Physics
, 88(5), 054422.
Sanna S., Carretta P., De Renzi R., Prando G., Bonfà P., Mazzani M., Lamura G., Shiroka T., Kobayashi Y., Sato M. (2013), Onset of magnetism in optimally electron-doped LFe(1−x)RuxAsO(1−y)Fy (L=La, Nd, or Sm) superconductors around x=1/4, in Physical Review B
, 87(13), 134518.
Sanna S., Carretta P., De Renzi R., Prando G., Bonfà P., Mazzani M., Lamura G., Shiroka T., Kobayashi Y., Sato M. (2013), Onset of magnetism in optimally electron-doped LFe1-xRu xAsO1-yFy (L=La, Nd, or Sm) superconductors around x=14, in Physical Review B - Condensed Matter and Materials Physics
, 87(13), 134518.
Glazkov V. N., Casola F., Ott H. R., Shiroka T. (2013), Phase diagram of low-dimensional antiferromagnets with competing order parameters: A Landau-theory approach, in Physical Review B - Condensed Matter and Materials Physics
, 87(5), 054427.
Prando G., Vakaliuk O., Sanna S., Lamura G., Shiroka T., Bonfà P., Carretta P., De Renzi R., Klauss H.-H, Blum C. G. F., Wurmehl S., Hess C., Büchner B. (2013), Role of in-plane and out-of-plane dilution in CeFeAsO: Charge doping versus disorder, in Physical Review B - Condensed Matter and Materials Physics
, 87, 174519.
Lamura G., Shiroka T., Bonfà P., Sanna S., De Renzi R., Baines C., Luetkens H., Kajitani J., Mizuguchi Y., Miura O., Deguchi K., Demura S., Takano Y., Putti M. (2013), s-wave pairing in the optimally doped LaO0.5F0.5BiS2 superconductor, in Physical Review B - Condensed Matter and Materials Physics
, 88(18), 180509.
Saadaoui H., Shiroka T., Amato A., Baines C., Luetkens H., Pomjakushina E., Pomjakushin V., Mesot J., Pikulski M., Morenzoni E. (2013), μsR and NMR study of the superconducting Heusler compound YPd2Sn, in Physical Review B - Condensed Matter and Materials Physics
, 88(9), 094518.
Shiroka T., Casola F., Mesot J., Bachmann W., Ott H. R. (2012), A two-axis goniometer for low-temperature nuclear magnetic resonance measurements on single crystals, in Review of Scientific Instruments
, 83(9), 093901.
Casola F., Shiroka T., Glazkov V., Feiguin A., Dhalenne G., Revcolevschi A., Zheludev A., Ott H. R., Mesot J. (2012), Dimensional crossover of spin chains in a transverse staggered field: An NMR study, in Physical Review B - Condensed Matter and Materials Physics
, 86(16), 165111.
Shiroka T., Casola F., Glazkov V., Zheludev A., Revcolevschi A., Dhalenne G., Prša K., Ott H. R., Mesot J. (2012), Experimental investigation of the low-temperature features of a random Heisenberg spin chain, in Journal of Physics: Conference Series
, 400(3), 032089.
The omnipresent thermal agitation excludes macroscopic quantum phenomena from our everyday experience. Close to the absolute zero, though, quantum coherence is preserved and transitions between different states of matter driven by quantum rather than thermal fluctuations are possible. Quantum phase transitions (QPTs), which connect competing ground states, provide new insights into long-standing problems related to, i.e., strong correlation and entanglement in condensed matter. Consequences of a quantum critical point, extended to finite temperatures, are believed to underlie the physics of systems such as high-temperature superconductors, heavy-fermion compounds, transition metal oxides, or metamagnetic materials.The aim of the present project is to address, mainly through magnetic resonance techniques, but also by other complementary experimental methods, the behaviour of materials close to a quantum critical point, with a particular regard to the dynamics of their elementary excitations.The unique possibility of performing NMR experiments in the extreme environment required to access the quantum critical regime (including ultra-low temperature, high pressure and high magnetic fields), make NMR one of the best experimental tools to explore quantum criticality. The present project is characterized by the following key features:Focus and Novelty: Our research will concentrate mainly on NMR/NQR investigations of strongly correlated electron systems in the proximity of a quantum critical transition. The often difficult study of the dynamics of quantum criticality (due to limitations of the experimental tools) will represent the distinguishing trait of the current project.Feasibility and Timing: Although we plan to investigate matter in challenging conditions, the current project is firmly grounded on previous experience and relies on well mastered experimental techniques. The wide scope of the research would require a 3-year period and will involve two PhD students.Teamwork: The proposed research will rely on existing and new collaborations involving material scientists, condensed matter theorists and international collaborators. This type of approach is particularly rewarding in investigating complex condensed matter.Impact and Perspective: Our experiments, to be carried out on different systems, will provide new insights into the respective low-temperature domains, possibly allowing us to extrapolate the common features of the various quantum phase diagram. Ultimately, our contribution would help to understand how competing orders interact in strongly correlated electronic systems.