Related papers: Magnetic Field Dependence of the Spin Fluctuations…
Resistivity measurements are widely exploited to uncover electronic excitations and phase transitions in metallic solids. While single crystals are preferably studied to explore crystalline anisotropies, these usually cancel out in…
Overdoped cuprate superconductors are strange metals above their superconducting transition temperature. In such materials, the electrical resistivity has a strong linear dependence on temperature ($T$) and electrical current is not carried…
Phase transitions occur when a macroscopic number of local degrees of freedom coherently change their behavior. In ground states of quantum many-body systems, phase transitions due to quantum fluctuations are observed as non-analytic…
Fluctuations are important near phase transitions, where they can be difficult to describe quantitatively. Superconductivity in mesoscopic rings is particularly intriguing because the critical temperature is an oscillatory function of…
The universality of the strange metal phase in many quantum materials is often attributed to the presence of a quantum critical point (QCP), a zero-temperature phase transition ruled by quantum fluctuations. In cuprates, where…
Ground-state fluctuations reduce the zero-temperature magnetic moments of the spins in a quantum antiferromagnet. In the neighborhood of surfaces, interfaces, and other defects which break translational symmetry, these fluctuations are not…
Anisotropy in strongly correlated materials is a central parameter in determining the electronic ground state and is tuned through the local crystalline electric field. This is notably the case in the CeCo$_{x}$Rh$_{1-x}$In$_{5}$ system…
The mechanism of how critical end points of the first-order valence transitions (FOVT) are controlled by a magnetic field is discussed. We demonstrate that the critical temperature is suppressed to be a quantum critical point (QCP) by a…
We study theoretically the effect of an external field on the nematic-smectic-A (NA) transition close to the tricritical point, where fluctuation effects govern the qualitative behavior of the transition. An external field suppresses…
Fluctuations of quantum spins play a crucial role in the emergence of exotic magnetic phases and excitations. The lack of the charge degree of freedom in insulating quantum magnets, however, precludes such fluctuations from mediating…
Materials with large magnetocrystalline anisotropy and strong electric field effects are highly needed to develop new types of memory devices based on electric field control of spin orientations. Instead of using modified transition metal…
The field induced quantum phase transitions in the disorder-free and disordered samples of the spin ladder material (CH_3)_2CHNH_3Cu(Cl_{1-x}Br_x)_3 are studied using magnetic calorimetry and magnetic neutron diffraction on single crystal…
Quantum transport phenomena allow experimental assessment of the phase coherence information in metals. We report quantitative comparisons of coherence lengths inferred from weak localization magnetoresistance measurements and…
We present macroscopic experimental evidence for field-induced microscopic quantum fluctuations in different hole- and electron-type cuprate superconductors with varying doping levels and numbers of CuO$_2$ layers per unit cell. The…
A quantum critical point is approached by applying pressure in a number of magnetic metals. The observed dependence of Tc on pressure necessarily means that the magnetic energy is coupled to the lattice. A first order phase transition…
Field-dependent specific heat and neutron scattering measurements were used to explore the antiferromagnetic S=1/2 chain compound CuCl2 * 2((CD3)2SO). At zero field the system acquires magnetic long-range order below TN=0.93K with an…
Identification of pairing mechanisms leading to the unconventional superconductivity realized in copper-oxide, heavy-fermions, and organic compounds is one of the most challenging issues in condensed-matter physics. Clear evidence for an…
Magnetic field dependences of critical current, resistance, and rectified voltage of asymmetric (half circles of different widths) and symmetrical (half circles of equal widths) aluminum rings were measured in the temperature region close…
We present the results of elastic and inelastic neutron scattering measurements on non-superconducting Ba(Fe${_{0.957}}$Cu${_{0.043}}$)${_2}$As${_2}$, a composition close to a quantum critical point between AFM ordered and paramagnetic…
The new integrable quantum spin model is proposed. The model has a biaxial magnetic anisotropy of alternating coupling between spins together with multiple spin interactions. Our model gives the possibility to exactly find thermodynamic…