Related papers: Quantum Fluctuations and the Exchange Bias Field
We study quantum Ising spins placed on small-world networks. A simple model is considered in which the coupling between any given pair of spins is a nonzero constant if they are linked in the small-world network and zero otherwise. By…
We study the effect of site dilution and quantum fluctuations in an antiferromagnetic spin system on a square lattice within the linear spin-wave approximation. By performing numerical diagonalization in real space and finite-size scaling,…
Quantum fluctuations are ubiquitous in physics. Ranging from conventional examples like the harmonic oscillator to intricate theories on the origin of the universe, they alter virtually all aspects of matter -- including superconductivity,…
It is shown how the exchange interaction, the dipole-dipole interaction, and the Dzyaloshinsky-Moriya interaction between electronic spin-density fluctuations emerge naturally from a field-theoretic framework that couples electrons to the…
Fluctuations of local fields cause decoherence of quantum objects. It is generally believed that at high temperatures, thermal noises are much stronger than quantum fluctuations unless the thermal effects are suppressed by certain…
Correlation effects in CuO$_2$ layers give rise to a complicated landscape of collective excitations in high-T$_{\rm c}$ cuprates. Their description requires an accurate account for electronic fluctuations at a very broad energy range and…
We generalize the Fredrickson-Helfand theory of the microphase separation in symmetric diblock copolymer melts by taking into account the influence of a time-independent homogeneous electric field on the composition fluctuations within the…
When a quantum many-particle system exists on a randomly diluted lattice, its intrinsic thermal and quantum fluctuations coexist with geometric fluctuations due to percolation. In this paper, we explore how the interplay of these…
We study the effects of a static and uniform magnetic field on the evolution of energy density fluctuations present in a medium. By numerically solving the relativistic Boltzmann-Vlasov equation within the relaxation time approximation, we…
Motivated by recent experiments reporting superconductivity only at very low temperature in a class of heavy fermion compounds, we study the impact of energy fluctuations with small momentum transfer on the pairing instability near an…
Monte Carlo simulations of a system consisting of a ferromagnetic layer exchange coupled to a diluted antiferromagnetic layer described by a classical spin model show a strong dependence of the exchange bias on the degree of dilution in…
Fluctuating electric fields emanating from surfaces are a primary source of decoherence in trapped ion qubits. Here, we show that superradiant phonon-induced excitation exchange between adatoms can lead to a reduction of electric field…
The magnetic properties of Co (<D>=15 nm, <L>=130nm) nanowires are reported. In oxidized wires, we measure large exchange bias fields of the order of 0.1 T below T ~ 100 K. The onset of the exchange bias, between the ferromagnetic core and…
We study fluctuation electromagnetic interaction between small neutral rotating particle and polarizable surface. The attraction force, friction torque and heating are produced by the particle polarization and fluctuating near-field of the…
Quantum coherence of electrons in ferromagnetic metals is difficult to assess experimentally. We report the first measurements of time-dependent universal conductance fluctuations in ferromagnetic metal (Ni$_{0.8}$Fe$_{0.2}$) nanostructures…
The expression of the thermal fluctuation parameter in the stochastic Landau-Lifshitz-Gilbert equation has been derived from a fundamental quantum theory of spins and phonons, in which the exchange interaction between nearest atoms has been…
The phenomenon of quantum nucleation is studied in a nanometer-scale antiferromagnet with biaxial symmetry in the presence of a magnetic field at an arbitrary angle. Within the instanton approach, we calculate the dependence of the rate of…
This work is about fluctuations of the surface charge between two media with distinct dielectric functions. The long-range correlation of the surface charge fluctuations is treated classically and quantum mechanically, in the non-retarded…
This paper provides a simple derivation of the decoherence rate for a diamagnetic nanoparticle in the presence of fluctuations of the magnetic field in a thermal environment. Diamagnetic levitation is one of the key techniques for trapping,…
Magnetic properties of core-shell cobalt ferrite nanoparticles 15 to 48nm prepared by a sol-gel route have been studied. It is shown that the coercivity follows non-monotonic size dependence varying as 1/d above the maximum (d is the…