Related papers: Quantum criticality in ferroelectrics
We present molecular dynamics simulations of a realistic model of an ultrathin film of BaTiO$_3$ sandwiched between short-circuited electrodes to determine and understand effects of film thickness, epitaxial strain and the nature of…
An effective field theory is derived for the ferromagnetic transition of diffusive electrons at T=0. The static disorder which leads to diffusive electron dynamics induces an effective long-range interaction between the spins of the form…
In this work, we present the studies of structural phase transitions in Fe(Se,Te) crystals in the range of about 30% selenium substitution by tellurium. We found a significant change in the properties of the ordered state of these…
The behavior of the conductivity and the density of states, as well as the phase relaxation time, of disordered itinerant electrons across a quantum ferromagnetic transition is discussed. It is shown that critical fluctuations lead to…
We calculate the low temperature one-particle scattering rate and the specific heat in a weakly disordered metal close to a quantum critical point. To lowest order in the fluctuation potential, we obtain typical Fermi-liquid results…
The consideration of size-induced ferroelectric-paraelectric phase transition for conventional and incipient ferroelectrics thin films with perovskite structure was carried out in phenomenological theory framework of…
The point at absolute zero where matter becomes unstable to new forms of order is called a quantum critical point (QCP). The quantum fluctuations between order and disorder that develop at this point induce profound transformations in the…
Using path-integral Monte Carol simulations and an ab initio effective Hamiltonian, we study the effects of quantum fluctuations on structural phase transitions in the cubic perovskite compounds SrTiO3 and BaTiO3. We find quantum…
Quantum-critical behavior of the itinerant electron antiferromagnet (V0.9Ti0.1)2O3 has been studied by single-crystal neutron scattering. By directly observing antiferromagnetic spin fluctuations in the paramagnetic phase, we have shown…
We report measurements of in-plane electrical and thermal transport properties in the limit $T \rightarrow 0$ near the unconventional quantum critical point in the heavy-fermion metal $\beta$-YbAlB$_4$. The high Kondo temperature $T_K$…
Small changes in an external parameter can often lead to dramatic qualitative changes in the lowest energy quantum mechanical ground state of a correlated electron system. In anisotropic crystals, such as the high temperature…
Polycrystalline sample of (Ba_{0.90}Pb_{0.10})(Ti_{0.90}Sn_{0.10})O_3 was obtained by means of a conventional ceramic technology. The dielectric measurements were performed depending on temperature and frequency of electric measuring field.…
Many functionally relevant ferroic phenomena in quantum materials can be manipulated by driving the lattice coherently with optical and terahertz pulses. New physical phenomena and non-equilibrium phases that have no equilibrium counterpart…
We study a model SrTiO$_3$ interface in which conduction $t_{2g}$ electrons couple to the ferroelectric (FE) phonon mode. We treat the FE mode within a self-consistent phonon theory that captures its quantum critical behavior, and show that…
The signature for a non-Fermi liquid behavior near a quantum phase transition has been observed in thermal and transport properties of many metallic systems at low temperatures. In the present work we consider specific examples of itinerant…
We give a general introduction to quantum phase transitions in strongly-correlated electron systems. These transitions which occur at zero temperature when a non-thermal parameter $g$ like pressure, chemical composition or magnetic field is…
Ferroelectricity is characterized by the presence of spontaneous and switchable macroscopic polarization. Scaling limits of ferroelectricity have been of both fundamental and technological importance, but the probes of ferroelectricity have…
Hexagonal ferrites do not only have enormous commercial impact ({\pounds}2 billion/year in sales) due to applications that include ultra-high density memories, credit card stripes, magnetic bar codes, small motors and low-loss microwave…
Ultra-dense domain walls are increasingly important for many devices but their microscopic properties are so far not fully understood. Here we use molecular dynamic simulations to study the domain wall stability in the prototypical…
In quantum materials, degeneracies and frustrated interactions can have a profound impact on the emergence of long-range order, often driving strong fluctuations that suppress functionally relevant electronic or magnetic phases. Engineering…