Related papers: Isotope effect in quasi-two-dimensional metal-orga…
We show that in anisotropic superconductors, falling at finite temperature into the 3D-XY- and at zero temperature into the 2D-XY-QSI universality class, the isotope effects on transition temperature, specific heat and magnetic penetration…
We show that the unusual doping dependence of the isotope effects on transition temperature and zero temperature in - plane penetration depth naturally follows from the doping driven 3D-2D crossover, the 2D quantum superconductor to…
A prominent character of two-dimensional magnetic systems is the enhanced spin fluctuations, which however reduce the ordering temperature. Here we report that a magnetic field of only one-thousandth of the Heisenberg superexchange…
We study cuprates within Dynamical Cluster Approximation and find the pseudogap displays an isotope effect of the same sign as observed experimentally. Notwithstanding the non-phononic origin of the pseudogap the interplay between…
Developing a theory of high-temperature superconductivity in copper oxides is one of the outstanding problems in physics. Twenty-five years after its discovery, no consensus on the microscopic theory has been reached despite tremendous…
Quantum effects in condensed matter normally only occur at low temperatures. Here we show a large quantum effect in high-pressure liquid hydrogen at thousands of Kelvins. We show that the metallization transition in hydrogen is subject to a…
In conventional superconductors, the electron pairing that allows superconductivity is caused by exchange of virtual phonons, which are quanta of lattice vibration. For high-transition-temperature (high-Tc) superconductors, it is far from…
Replacement of hydrogen by deuterium in palladium hydride results in higher superconducting temperatures and an anomalous isotope effect that has not been yet fully explained. In this work, we try a new approach to the explanation of the…
The effect of the 16O-->18O substitution on the superconducting transition temperatures Tc of NaxCoO2.yH2O has been studied for several sets of samples. Each set has two kinds of samples, one with the oxygen sites in the CoO2 layers filled…
Based on recently proposed anti-ferromagnetic spin fluctuation exchange models for $d_{x^2-y^2}$-superconductors, we show that coupling to harmonic phonons {\it{cannot}} account for the observed isotope effect in the cuprate high-$T_c$…
We report an extraordinary pressure dependence of the magnetic interactions in the metal-organic system [(CuF$_2$(H$_2$O)$_2$)$_2$pyrazine]. At zero pressure, this material realizes a quasi-two-dimensional (Q2D) spin-1/2 square-lattice…
Heterostructures from complex oxides allow one to combine various electronic and magnetic orders as to induce new quantum states. A prominent example is the coupling between superconducting and magnetic orders in multilayers from high-Tc…
Superconductivity in the heavy-fermion metal UTe2 survives the application of very high magnetic fields, presenting both an intriguing puzzle and an experimental challenge. The strong, non-perturbative influence of the magnetic field…
We have employed uniaxial stress along the principal axes of the quasi-two dimensional organic superconductor $\kappa $--(BEDT-TTF)$_{2}$Cu(SCN)$_{2}$. The lattice anisotropy is thereby altered, with corresponding changes in the…
TThe isotope effect is a powerful probe of electron-phonon interactions in solid-state systems, offering key insights into how atomic mass influences emergent quantum states. Here, the impact of oxygen isotope substitution ($^{16}{\rm…
It is shown that the translation-invariant bipolaron theory of superconductivity can explain the dependence of the isotope coefficient in high-temperature superconductors on the critical temperature of a superconducting transition: in the…
Type II superconductors, consisting of superconducting domains embedded in a normal or insulating matrix, undergo a rounded phase transition. Indeed, the correlation length cannot grow beyond the spatial extent of the domains. Accordingly,…
A compact expression has been obtained for the superexchange coupling of magnetic ions via intermediate anions with regard to polaron effects at both magnetic ions and intermediate anions. This expression is used to analyze the main…
We analyze the data for the pressure and boron isotope effect on the temperature dependence of the magnetization near $T_{c}$. Invoking the universal scaling relation for the magnetization at fixed magnetic field it is shown that the…
We have studied the oxygen-isotope effect on the superconducting transition temperature $T_{c}$ in overdoped Y$_{1-x}$Ca$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-\delta}$ with $x$ = 0.10, 0.20, and 0.25. We find the oxygen-isotope exponent $\alpha_{O}$…