I. S. Beloborodov

Granular electronic systems

Granular metals are arrays of metallic particles of a size ranging usually from a few to hundreds of nanometers embedded into an insulating matrix. Metallic granules are often viewed as artificial atoms. Accordingly, granular arrays can be treated as artificial solids with programmable electronic properties. The ease of adjusting electronic properties of granular metals assures them an important role for nanotechnological applications and makes them most suitable for fundamental studies of disordered solids. This review discusses recent theoretical advances in the study of granular metals, emphasizing the interplay of disorder, quantum effects, fluctuations, and effects of confinement. These key elements are quantified by the tunneling conductance between granules

Multiple cotunneling in large quantum dot arrays.

g

Sequential tunneling and inelastic cotunneling in nanoparticle arrays

, the charging energy of a single granule

Transport properties of granular metals at low temperatures.

{E}_{c}

Transport properties of n-type ultrananocrystalline diamond films

, the mean level spacing within a granule

Negative magnetoresistance of granular metals in a strong magnetic field

\ensuremath{\delta}

Universal description of granular metals at low temperatures: granular Fermi liquid

, and the mean electronic lifetime within the granule

Magnetoresistance of granular superconducting metals in a strong magnetic field

\ensuremath{\hbar}∕g\ensuremath{\delta}

Electron transport in nanogranular ferromagnets

. By tuning the coupling between granules the system can be made either a good metal for

Thermal transport in granular metals

gg{g}_{c}=(1∕2\ensuremath{\pi}d)\mathrm{ln}({E}_{c}∕\ensuremath{\delta})