Publications de Kazimierz Conder

A quantum magnetic analogue to the critical point of water

Henrik Moodysson Rønnow, Frédéric Mila, Bruce Normand, Christian Rüegg, Ludger Weber, Ellen Fogh, Mohamed Zayed, Julio Antonio Larrea Jiménez, Kazimierz Conder

At the liquid-gas phase transition in water, the density has a discontinuity at atmospheric pressure; however, the line of these first-order transitions defined by increasing the applied pressure terminates at the critical point(1), a concept ubiquitous in ...

2021

Evidence of a Coulomb-Interaction-Induced Lifshitz Transition and Robust Hybrid Weyl Semimetal in Td−MoTe2

Arnaud Magrez, Jan Hugo Dil, Helmuth Berger, Joël Mesot, Philippe Bugnon, Kazimierz Conder

2018

Observation of Weyl nodes and Fermi arcs in tantalum phosphide

Oleg Yazyev, Joël Mesot, Gabriel Albert Autes, Kazimierz Conder

A Weyl semimetal possesses spin-polarized band-crossings, called Weyl nodes, connected by topological surface arcs. The low-energy excitations near the crossing points behave the same as massless Weyl fermions, leading to exotic properties like chiral anom ...

Nature Publishing Group2016

Spiral magnetic phase in Li-doped Na2IrO3

Sándor Tóth, Kazimierz Conder

The doping of the honeycomb lattice compound Na2IrO3 with cations having smaller ionic radius such as lithium was supposed to drive the system into a Kitaev spin liquid phase. Even at the smallest doping level the long range magnetic order, present in the ...

American Physical Society2015

Probing the electron-phonon interaction in correlated systems with coherent lattice fluctuation spectroscopy

Fabrizio Carbone, Frank van Mourik, Edoardo Baldini, Christopher Alexander Arrell, Andreas Helmut Christian Mann, Kazimierz Conder

Tailoring the properties of correlated oxides is accomplished by chemical doping, pressure, temperature, or magnetic field. Photoexcitation is a valid alternative to reach out-of-equilibrium states otherwise inaccessible. Here, we quantitatively estimate t ...

Amer Physical Soc2015

Direct observation of the spin texture in SmB6 as evidence of the topological Kondo insulator

Jan Hugo Dil, Joël Mesot, Stefan Peter Muff, Kazimierz Conder

Topological Kondo insulators have been proposed as a new class of topological insulators in which non-trivial surface states reside in the bulk Kondo band gap at low temperature due to strong spin-orbit coupling. In contrast to other three-dimensional topo ...

Nature Publishing Group2014

Exotic Kondo crossover in a wide temperature region in the topological Kondo insulator SmB6 revealed by high-resolution ARPES

Jan Hugo Dil, Joël Mesot, Kazimierz Conder

Temperature dependence of the electronic structure of SmB6 is studied by high-resolution angle-resolved photoemission spectroscopy (ARPES) down to 1 K. We demonstrate that there is no essential difference for the dispersions of the surface states below and ...

Amer Physical Soc2014

Quantum and thermal ionic motion, oxygen isotope effect, and superexchange distribution in La2CuO4

Henrik Moodysson Rønnow, Sandrine Gerber, Bastien Dalla Piazza, Bruce Normand, Vera Irina Schnells, Kazimierz Conder

We study the zero-point and thermal ionic motion in La2CuO4 by means of high-resolution neutron-diffraction experiments. Our results demonstrate anisotropic motion of O and, to a lesser extent, Cu ions, both consistent with the structure of coupled CuO6 oc ...

2014

Correlated Decay of Triplet Excitations in the Shastry-Sutherland Compound SrCu2(BO3)(2)

Henrik Moodysson Rønnow, Joël Mesot, Mohamed Zayed, Kazimierz Conder

The temperature dependence of the gapped triplet excitations (triplons) in the 2D Shastry-Sutherland quantum magnet SrCu2(BO3)(2) is studied by means of inelastic neutron scattering. The excitation amplitude rapidly decreases as a function of temperature, ...

American Physical Society2014

Temperature dependence of the pressure induced monoclinic distortion in the spin S=1/2 Shastry-Sutherland compound SrCu2(BO3)(2)

Henrik Moodysson Rønnow, Mohamed Zayed, Kazimierz Conder

We investigate the monoclinic distortion that occurs at 4.7 GPa at room temperature in the frustrated Shastry-Sutherland model quantum magnet SrCu2(BO3)(2) as a function of pressure and temperature by means of powder and single crystal angle dispersive syn ...

Elsevier2014