Related papers: Macroscopic quantum coherence in antiferromagnetic…
Coherent resonant tunneling through an artificial molecule of quantum dots in an inhomogeneous magnetic field is investigated using an extended Hubbard model. Both the multiterminal conductance of an array of quantum dots and the persistent…
Field-tuned quantum tunneling in two single-molecule magnets coupled antiferromagnetically and formed a supramolecule dimer is studied. We obtain step-like magnetization curves by means of the numerically exact solution of the…
Highly accurate numerical results for single-particle spectrum and order parameter are obtained for the magnetically ordered Kondo lattice by means of the dynamical mean-field theory combined with the continuous-time quantum Monte Carlo…
The quantum tunneling of the magnetization vector are studied theoretically in single-domain ferromagnetic nanoparticles placed in an external magnetic field at an arbitrarily directed angle in the $ZX$ plane. We consider the…
We study classical and quantum Heisenberg antiferromagnets with exchange anisotropy of XXZ-type and crystal field single-ion terms of quadratic and cubic form in a field. The magnets display a variety of phases, including the spin-flop (or,…
The Landau Zener model has recently been used to measure very small tunnel splittings in molecular clusters of Fe8, which at low temperature behaves like a nanomagnet with a spin ground state of S = 10. The observed oscillations of the…
From inelastic neutron scattering experiments, we demonstrate quantum tunneling of the Neel vector in the antiferromagnetic molecular ferric wheel CsFe8. Analysis of the linewidth of the tunneling transition evidences coherent tunneling.
Recent microwave experiments demonstrate the anapole-moment and magnetoelectric properties in quasi-2D ferrite particles with magnetic-dipolar-wave oscillating spectra. The theory developed in this paper shows that there are the…
New macroscopic quantum interference effects in the behavior of the antiferromagnetic nanoclusters under action of a swept magnetic field are predicted and theoretically investigated, namely : oscillations of the magnetic susceptibility of…
In recent years, studies on cyclic molecular nanomagnets have captivated the attention of researchers. These magnets are finite in size and contain very large spins. They are interesting because they possess macroscopic quantum tunneling of…
We examine the robustness of a recently predicted exchange-induced zero-field magnetic phase in semiconductor double quantum wells in which each well is spin-polarized and the polarization vectors are antiparallel. Magnetic instabilities…
We measure the low-temperature resistance of permalloy break junctions as a function of contact size and the magnetic field angle, in applied fields large enough to saturate the magnetization. For both nanometer-scale metallic contacts and…
Molecular nanomagnets, besides promising to open new frontiers in technology, have attracted huge interest in the scientific community because they can exhibit the phenomenon known as quantum tunnelling of the magnetization, i.e. coherent…
The theory for the quantum tunneling of nano-magnets is developed within the intermediate spin framework. Periodic magnetic effects are seen to reflect that associated with a change of flux by a single flux quantum $\Phi_{0}$. Essential are…
We have investigated analytically quantum tunneling of large spin in the biaxial spin system with the magnetic field applied along the hard and medium anisotropy axes by using a purely quantum-mechanical approach. When the magnetic field…
In this paper we investigate the macroscopic quantum tunnelling and the phase coherence property of the rotating Bose-Einstein condensates in both static and dynamic cases by using the mean field theory.
Magnetization measurements of Mn12 molecular nanomagnets with spin ground states of S = 10 and S = 19/2 showresonance tunneling at avoided energy level crossings. The observed oscillations of the tunnel probability as a function of the…
We present a review of suppression of tunneling rate (energy splitting) for half-odd-integer spins in ferromagnetic and antiferromagnetic particles. We also review the quenching of the tunneling rate in the presence of a magnetic field.
Quantum decoherence is the key mechanism determining whether quantum effects can manifest in quantum computation and transport, and mastering decoherence is central to designing and operating functional quantum devices. Here, we present a…
The evolution of the quantum wave packet describing an atom trapped in the surface-tip junction of the scanning tunneling microscope is investigated by using the time-dependent Schroedinger equation, and by a quasi-classical Hamiltonian…