Related papers: Dipolar Ordering and Quantum Dynamics of Domain Wa…
Dipolar coupling in crystals of the Mn$_{12}$Ac molecular magnet elongated along the anisotropy axis favors ferromagnetic ordering below the mean-field Curie temperature 0.71 K. With the help of Monte Carlo on crystals of up to one million…
Ordering in realistic elongated box-shape crystals of the molecular magnet Mn_12 Ac is investigated with the site-resolved mean-field approximation that does not assume a uniform ordering. It is shown that ferromagnetic ordering should not…
Crystals of the molecular magnet Mn12-acetate are known to contain a small fraction of low- symmetry (minor) species with a small anisotropy barrier against spin reversal. The lower barrier leads to faster magnetic relaxation and lower…
We show that the low-temperature physics of molecular nanomagnets, contrary to the prevailing one-molecule picture, must be determined by the long-range magnetic ordering due to many-body dipolar interactions. The calculations here…
At high densities fluids of strongly dipolar spherical particles exhibit spontaneous long-ranged orientational order. Typically, due to demagnetization effects induced by the long range of the dipolar interactions, the magnetization…
We use neutron diffraction to probe the magnetization components of a crystal of Mn12 single-molecule magnets. Each of these molecules behaves, at low temperatures, as a nanomagnet with spin S = 10 and strong anisotropy along the…
The longitudinal magnetic susceptibility of single crystals of the molecular magnet Mn$_{12}$-acetate obeys a Curie-Weiss law, indicating a transition to a ferromagnetic phase due to dipolar interactions. With increasing magnetic field…
We investigate the formation of stable one-dimensional N\'eel walls in a ferromagnetic slab with finite thickness and finite width. Taking into account the dipolar, the exchange and the uniaxial anisotropic crystalline field interactions,…
Few examples of magnetic systems displaying a transition to pure dipolar magnetic order are known to date, and single-molecule magnets can provide an interesting example. The molecular cluster spins and thus their dipolar interaction energy…
Recent advances in cold atom experimentation suggest that studies of quantum two-dimensional melting of dipolar molecules, with dipoles aligned perpendicular to ordering plane, may be on the horizon. An intriguing aspect of this problem is…
Comprehensive theory of quantum spin relaxation in Mn-12 acetate crystals is developed, that takes into account imperfections of the crystal structure and is based upon the generalization of the Landau-Zener effect for incoherent tunneling…
We investigate magnetic domain walls in a single fcc Mn layer on Re(0001) employing spin-polarized STM, atom manipulation, and spin dynamics simulations. The low symmetry of the row-wise antiferromagnetic (1Q) state leads to a new type of…
We show that nano-scale variations of the order parameter in strongly-correlated systems can induce local spatial regions such as domain walls that exhibit electronic properties representative of a different, but nearby, part of the phase…
Surface interactions are responsible for many properties of condensed matter, ranging from crystal faceting to the kinetics of phase transitions. Usually, these interactions are polar along the normal to the interface and apolar within the…
Dissipative spin-tunneling transitions at biased resonances in molecular magnets such as Mn-12 Ac are controlled by the dipolar field that can bring the system on and off resonance. It is shown that this leads to spin relaxation in form of…
The realization of a spontaneous macroscopic ferroelectric order in fluids of anisotropic mesogens is a topic of both fundamental and technological interest. Recently, we demonstrated that a system of dipolar achiral disklike ellipsoids can…
We review our studies of the effect of transverse fields on the susceptibility and magnetization of single crystals of the prototype single molecule magnet (SMM), Mn$_{12}$-acetate, and of a new high-symmetry variant,…
We study the magnetic properties of small Mn ring shaped clusters on a Pt(111) surface in the framework of density functional theory. We find that the Mn atoms possess large magnetic moments, of the order of 4uB/atom, and have dominating…
We investigate in this paper the ground state and the nature of the transition from an orientational ordered phase at low temperature to the disordered state at high temperature in a molecular crystal. Our model is a Potts model which takes…
Materials with coupled or competing order parameters display highly tunable ground states, where subtle perturbations reveal distinct electronic and magnetic phases. These phases generally are underpinned by complex crystal structures, but…