Interacting Electrons

Yosuke Sato, Sadashige Matsuo, Chen-Hsuan Hsu +12 more

We report strong electron-electron interactions in quantum wires etched from an InAs quantum well, a material generally expected to have strong spin-orbit interactions. We find that the current through the wires as a function of the bias voltage and temperature follows the universal scaling behavior of a Tomonaga-Luttinger liquid. Using a universal scaling formula, we extract the interaction parameter and find strong electron-electron interactions, increasing as the wires become more depleted. We establish theoretically that the spin-orbit interaction cause only minor modifications of the interaction parameter in this regime, indicating that genuinely strong electron-electron interactions are indeed achieved in the device. Our results suggest that etched InAs wires provide a platform with both strong electron-electron interactions and the strong spin-orbit interaction.

Bing Gu, Ignacio Franco

The relationship between electronic interactions and electronic decoherence is a fundamental problem in chemistry. Here we show that varying the electron-electron interactions does not affect the electronic decoherence in the pure-dephasing limit. In this limit, the effect of varying the electronic interactions is to rigidly shift in energy the diabatic potential energy surfaces without changing their shape, thus keeping the nuclear dynamics in these surfaces that leads to the electronic decoherence intact. This analysis offers a simple and intuitive understanding of previous theoretical and computational efforts to characterize the influence of electronic interactions on the decoherence and opens opportunities to study exact electronic decoherence with approximate electronic structure theories.

John S. Kimball

A Hubbard model with randomised site energies is used to investigate electron localisation effect associated with both disorder and electron-electron interactions. The ground-state properties of this system are illustrated in a phase diagram. It is shown that electron localisation dominated by interactions is physically distinct from localisation dominated by disorder. Electrons localised through interactions have antiferromagnetic order (at T=0) and electrons localised primarily by disorder have a spin glass magnetic disorder. In this model, true non-magnetic Anderson localisation is a limiting case which applies only for non-interacting electrons.