Spontaneous orbital magnetization of mesoscopic dipole dimers

Abstract

Ensembles of gold nanoparticles present a magnetic behavior which is at odds with the weakly diamagnetic response of bulk gold. In particular, an unusual ferromagnetic order has been unveiled by several experiments. Here we investigate if the combined effect of orbital magnetism of conduction electrons and interparticle dipolar interaction can lead to magnetic ordering. Using different model systems of interacting mesoscopic magnetic dipoles, together with a microscopic description of the electron dynamics within the nanoparticles, we find that a spontaneous magnetic moment may arise in dimers of metallic nanoparticles when the latter are characterized by a large orbital paramagnetic susceptibility.

arXiv comment13 pages, 10 figures

References in corpus (15)

• Direct evidence for ferromagnetic spin polarization in gold nanoparticles
• Surface Plasmon Dispersion Relations in Chains of Metallic Nanoparticles: Exact Quasistatic Calculation
• Orbital Magnetism in the Ballistic Regime: Geometrical Effects
• Diameter dependence of ferromagnetic spin moment in Au nanocrystals
• Dipolar interaction between two-dimensional magnetic particles
• Lifetime of the first and second collective excitations in metallic nanoparticles
• Nonradiative limitations to plasmon propagation in chains of metallic nanoparticles
• Decay of dark and bright plasmonic modes in a metallic nanoparticle dimer
• Radiative frequency shifts in nanoplasmonic dimers
• Super Shell Structure of the Magnetic Susceptibility
• Dipolar ferromagnetism in three-dimensional superlattices of nanoparticles
• Orbital magnetism in ensembles of gold nanoparticles
• Quantum Size Effects in the Magnetic Susceptibility of a Metallic Nanoparticle
• Diamagnetism of metallic nanoparticles as the result of strong spin-orbit interaction
• Superconducting fluctuations--Large Diamagnetism of Low $T_c$ Nanoparticles