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Milena Grifoni

Publications and source records attributed to Milena Grifoni.

2 recordsLinked to original sources

Dynamical symmetry breaking in transport through molecules.

We analyze the interplay between vibrational and electronic degrees of freedom in charge transport across a molecular single-electron transistor. We focus on the wide class of molecules which possess quasidegenerate vibrational eigenstates, while no degeneracy occurs for their anionic configuration. We show that the combined effect of a thermal environment and coupling to leads, involving tunneling events charging and discharging the molecule, leads to a dynamical symmetry breaking where quasidegenerate eigenstates acquire different occupations. This imbalance gives rise to a characteristic asymmetry of the current versus an applied gate voltage.

Journal Article↗

Helicity and electron-correlation effects on transport properties of double-walled carbon nanotubes.

Starting from selection rules for intershell tunneling in double-walled nanotubes with commensurate (c-DWNTs) and incommensurate (i-DWNTs) shells, we show that for i-DWNTs the coupling is negligible between lowest energy subbands, but it becomes important as the higher subbands become populated. In turn the elastic mean-free path of i-DWNTs is reduced for increasing energy, with additional suppression at subband onsets and crossings. At low energies, a Luttinger liquid theory for DWNTs with metallic shells is derived. Interaction effects are more pronounced in i-DWNTs than in c-DWNTs.

Journal Article↗