Related papers: Magnetic field-tuned quantum criticality in optima…
Using ac composite magnetoelectric technique, we map the phase diagrams of EuFe(As1-xPx)2 to resolve the interplay between superconductivity and ferromagnetism. For samples with Tc<TFM, the transition to a ferromagnetic multi-domain state…
Neutron scattering measurements are used to elucidate interplay of the field-induced spin gap and the quantum fluctuations in archetypal heavy electron system CeCu$_{2}$Ge$_{2}$. A spin gap of $\Delta$ = 0.56 meV is found to develop near…
The transition temperature Tc of cuprate superconductors falls when the doping p is reduced below a certain optimal value. It is unclear whether this fall is due to strong phase fluctuations or to a decrease in the pairing gap. Different…
The electron-doped cuprates Pr_{2-x}Ce_xCuO_4 and Nd_{2-x}Ce_xCuO_4 have been studied by electronic Raman spectroscopy across the entire region of the superconducting (SC) phase diagram. The SC pairing strength is found to be consistent…
For YBa_2Cu_3O_{6+\delta} and Bi_2Sr_2CaCu_2O_8 superconductors, electronic Raman scattering from high- and low-energy excitations has been studied in relation to the hole doping level, temperature, and energy of the incident photons. For…
We performed nuclear magnetic resonance (NMR) measurements to investigate the evolution of spin-density-wave (SDW) and superconducting (SC) states upon electron doping in CaFe_{1-x}Co_{x}AsF, which exhibits an intermediate phase diagram…
Hydrogen (H)-doped LaFeAsO is a prototypical iron-based superconductor. However, its phase diagram extends beyond the standard framework, where a superconducting (SC) phase follows an antiferromagnetic (AF) phase upon carrier doping;…
We report a systematic study by 75As nuclear-quadrupole resonance in LaFeAsO1-xFx. The antiferromagnetic spin fluctuation (AFSF) found above the magnetic ordering temperature TN = 58 K for x = 0.03 persists in the regime 0.04 < x < 0.08…
Two critical points have been revealed in the normal-state phase diagram of the electron-doped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_4$ by exploring the Fermi surface properties of high quality single crystals by high-field…
Extending our previous studies we present results for the doping-, momentum-, frequency-, and temperature- dependence of the kink-like change of the quasiparticle velocity resulting from the coupling to spin fluctuations. In the nodal…
Spin transport in superconductors offers a compelling platform to merge the dissipationless nature of superconductivity with the functional promise of spin-based electronics. A significant challenge in achieving spin polarisation in…
The superconductivity phase diagrams of electron doped cuprates of the form R(2-x)CexCuO4 (with R= La, Pr, Nd, Sm, and Eu) have been determined for cerium compositions 0 < x < 0.36 in a consistent series of epitaxial thin films grown by…
Motivated by the evidence in PCCO and NCCO of a magnetic quantum critical point at which Neel order is destroyed, we study the evolution with doping of the T=0 quantum phases of the electron doped cuprates. At low doping, there is a…
In itinerant ferromagnets, the quenched disorder is predicted to dramatically affect the ferromagnetic to paramagnetic quantum phase transition driven by external control parameters at zero temperature. Here we report a study on Fe-doped…
The mysterious pseudogap phase of cuprate superconductors ends at a critical hole doping level p* but the nature of the ground state below p* is still debated. Here, we show that the genuine nature of the magnetic ground state in…
By extending previous work on the scaling of low frequency magnetic properties of the 2-1-4 cuprates to the 1-2-3 materials, we arrive at a consistent phenomenological description of protected behavior in the pseudogap state of the…
Bi-based cuprate superconductors are important materials for both fundamental research and applications. As in other cuprates, the superconducting phase in the Bi compounds lies close to an antiferromagnetic phase. Our density functional…
Substitutional impurities in the CuO2 planes of the cuprates allow us to probe the electronic properties of the host material. The pseudo-gap in the underdoped regime is unmodified far from the impurities even though Tc is greatly reduced.…
Many emergent phenomena appear in doped Mott insulators near the insulator-to-metal transition. In high-temperature cuprate superconductors, superconductivity arises when antiferromagnetic (AFM) order is gradually suppressed by carrier…
Neutron scattering studies have provided important information about the momentum and energy dependence of magnetic excitations in cuprate superconductors. Of particular interest are the recent indications of a universal magnetic excitation…