TY - CONF AB - The aim of this short note is to expound one particular issue that was discussed during the talk [10] given at the symposium ”Researches on isometries as preserver problems and related topics” at Kyoto RIMS. That is, the role of Dirac masses by describing the isometry group of various metric spaces of probability measures. This article is of survey character, and it does not contain any essentially new results.From an isometric point of view, in some cases, metric spaces of measures are similar to C(K)-type function spaces. Similarity means here that their isometries are driven by some nice transformations of the underlying space. Of course, it depends on the particular choice of the metric how nice these transformations should be. Sometimes, as we will see, being a homeomorphism is enough to generate an isometry. But sometimes we need more: the transformation must preserve the underlying distance as well. Statements claiming that isometries in questions are necessarily induced by homeomorphisms are called Banach-Stone-type results, while results asserting that the underlying transformation is necessarily an isometry are termed as isometric rigidity results.As Dirac masses can be considered as building bricks of the set of all Borel measures, a natural question arises:Is it enough to understand how an isometry acts on the set of Dirac masses? Does this action extend uniquely to all measures?In what follows, we will thoroughly investigate this question. AU - Geher, Gyorgy Pal AU - Titkos, Tamas AU - Virosztek, Daniel ID - 7035 T2 - Kyoto RIMS Kôkyûroku TI - Dirac masses and isometric rigidity VL - 2125 ER - TY - JOUR AB - A recent class of topological nodal-line semimetals with the general formula MSiX (M = Zr, Hf and X = S, Se, Te) has attracted much experimental and theoretical interest due to their properties, particularly their large magnetoresistances and high carrier mobilities. The plateletlike nature of the MSiX crystals and their extremely low residual resistivities make measurements of the resistivity along the [001] direction extremely challenging. To accomplish such measurements, microstructures of single crystals were prepared using focused ion beam techniques. Microstructures prepared in this manner have very well-defined geometries and maintain their high crystal quality, verified by the observations of quantum oscillations. We present magnetoresistance and quantum oscillation data for currents applied along both [001] and [100] in ZrSiS and ZrSiSe, which are consistent with the nontrivial topology of the Dirac line-node, as determined by a measured π Berry phase. Surprisingly, we find that, despite the three dimensional nature of both the Fermi surfaces of ZrSiS and ZrSiSe, both the resistivity anisotropy under applied magnetic fields and the in-plane angular dependent magnetoresistance differ considerably between the two compounds. Finally, we discuss the role microstructuring can play in the study of these materials and our ability to make these microstructures free-standing. AU - Shirer, Kent R. AU - Modic, Kimberly A AU - Zimmerling, Tino AU - Bachmann, Maja D. AU - König, Markus AU - Moll, Philip J. W. AU - Schoop, Leslie AU - Mackenzie, Andrew P. ID - 7055 IS - 10 JF - APL Materials SN - 2166-532X TI - Out-of-plane transport in ZrSiS and ZrSiSe microstructures VL - 7 ER - TY - JOUR AB - We present a high magnetic field study of NbP—a member of the monopnictide Weyl semimetal (WSM) family. While the monoarsenides (NbAs and TaAs) have topologically distinct left and right-handed Weyl fermi surfaces, NbP is argued to be “topologically trivial” due to the fact that all pairs of Weyl nodes are encompassed by a single Fermi surface. We use torque magnetometry to measure the magnetic response of NbP up to 60 tesla and uncover a Berry paramagnetic response, characteristic of the topological Weyl nodes, across the entire field range. At the quantum limit B* (≈32 T), τ/B experiences a change in slope when the chemical potential enters the last Landau level. Our calculations confirm that this magnetic response arises from band topology of the Weyl pocket, even though the Fermi surface encompasses both Weyl nodes at zero magnetic field. We also find that the magnetic field pulls the chemical potential to the chiral n = 0 Landau level in the quantum limit, providing a disorder-free way of accessing chiral Weyl fermions in systems that are “not quite” WSMs in zero magnetic field. AU - Modic, Kimberly A AU - Meng, Tobias AU - Ronning, Filip AU - Bauer, Eric D. AU - Moll, Philip J. W. AU - Ramshaw, B. J. ID - 7057 IS - 1 JF - Scientific Reports SN - 2045-2322 TI - Thermodynamic signatures of Weyl fermions in NbP VL - 9 ER - TY - JOUR AB - In the Ca1−x La x FeAs2 (1 1 2) family of pnictide superconductors, we have investigated a highly overdoped composition (x  =  0.56), prepared by a high-pressure, high-temperature synthesis. Magnetic measurements show an antiferromagnetic transition at T N  =  120 K, well above the one at lower doping (0.15  <  x  <  0.27). Below the onset of long-range magnetic order at T N, the electrical resistivity is strongly reduced and is dominated by electron–electron interactions, as evident from its temperature dependence. The Seebeck coefficient shows a clear metallic behavior as in narrow band conductors. The temperature dependence of the Hall coefficient and the violation of Kohler's rule agree with the multiband character of the material. No superconductivity was observed down to 1.8 K. The success of the high-pressure synthesis encourages further investigations of the so far only partially explored phase diagram in this family of Iron-based high temperature superconductors. AU - Martino, Edoardo AU - Bachmann, Maja D AU - Rossi, Lidia AU - Modic, Kimberly A AU - Zivkovic, Ivica AU - Rønnow, Henrik M AU - Moll, Philip J W AU - Akrap, Ana AU - Forró, László AU - Katrych, Sergiy ID - 7056 IS - 48 JF - Journal of Physics: Condensed Matter SN - 0953-8984 TI - Persistent antiferromagnetic order in heavily overdoped Ca1−x La x FeAs2 VL - 31 ER - TY - JOUR AB - Although crystals of strongly correlated metals exhibit a diverse set of electronic ground states, few approaches exist for spatially modulating their properties. In this study, we demonstrate disorder-free control, on the micrometer scale, over the superconducting state in samples of the heavy-fermion superconductor CeIrIn5. We pattern crystals by focused ion beam milling to tailor the boundary conditions for the elastic deformation upon thermal contraction during cooling. The resulting nonuniform strain fields induce complex patterns of superconductivity, owing to the strong dependence of the transition temperature on the strength and direction of strain. These results showcase a generic approach to manipulating electronic order on micrometer length scales in strongly correlated matter without compromising the cleanliness, stoichiometry, or mean free path. AU - Bachmann, Maja D. AU - Ferguson, G. M. AU - Theuss, Florian AU - Meng, Tobias AU - Putzke, Carsten AU - Helm, Toni AU - Shirer, K. R. AU - Li, You-Sheng AU - Modic, Kimberly A AU - Nicklas, Michael AU - König, Markus AU - Low, D. AU - Ghosh, Sayak AU - Mackenzie, Andrew P. AU - Arnold, Frank AU - Hassinger, Elena AU - McDonald, Ross D. AU - Winter, Laurel E. AU - Bauer, Eric D. AU - Ronning, Filip AU - Ramshaw, B. J. AU - Nowack, Katja C. AU - Moll, Philip J. W. ID - 7082 IS - 6462 JF - Science SN - 0036-8075 TI - Spatial control of heavy-fermion superconductivity in CeIrIn5 VL - 366 ER -