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Antonio Carlos A. Ramos

Publications and source records attributed to Antonio Carlos A. Ramos.

2 recordsLinked to original sources

Self-consistent one-dimensional electron system on liquid helium suspended over a nanoscale dielectric substrate

For electrons above a superfluid helium film suspended on a specially designed dielectric substrate, $z=h(y)$, we obtain that both the transverse, along $z$, and the lateral, along $y$, quantizations are strongly enhanced due to a strong mutual coupling. The self-consistent quantum wires (QWs) with non-degenerated one-dimensional electron systems (1DESs) are obtained over a superfluid liquid helium (LH) suspended self-consistently on different dielectric substrates with a nanoscale modulation. A gap $\gtrsim 10$meV ($\gtrsim 1$meV) is obtained between the lowest two electron levels due to mainly the transverse (lateral) quantization. Our analytical model takes into account a strong interplay between the transverse and the lateral quantizations of an electron. It uses that the characteristic length (energy) along the former direction is essentially smaller (larger) than the one along the latter, in a close analogy with the adiabatic approximation.

cond-mat.mes-hall↗

Polaron states of electrons over the anisotropic surface of liquid helium

The energetics and transport properties of the polaron in the anisotropic surface over liquid helium are investigated. The localization radii and the energy of the ground and excited states are calculated using the variational method within the hydrodynamic model of the polaron. In particular, we have considered maximal anisotropy which corresponds to the system of electrons in quasi-one-dimensional channels over liquid helium. The polaron binding energy is found and the temperature for the polaron formation is estimated below 0.1 K. Solving the hydrodynamic equations for fluid velocities, the polaron mobilities along and across the channel are determined. The possibility of experimental observation of polarons by measuring the frequency of spectroscopic transitions as well the mobility as functions of the holding electric field is addressed.

cond-mat.str-el↗