Electrons in artificial atoms

Bohmian description of a decaying quantum system

“…The particle is initially confined inside the potential barrier and at a certain time, t = 0, it begins to leak out. The model and its variants can be used to simulate a decay process through tunneling such as the nuclear α decay [9] or the emission of an electron from an artificial atom (quantum dot) [10]. In order to apply Bohm's theory to such a system, one has to know the wave function of the system explicitly.…”

Photon Assisted Tunneling in Quantum Dots

“…Thermal broadening ∼ 4kBT /h 10 GHz (at 100 mK) If f ≪ Γ each electron sees an essentially static potential and we are in the adiabatic regime [2,18]. If f ≫ Γ, each electron experiences many cycles of the ac signal while it is on the dot; i.e.…”

“…In some studies finite, but still low frequency signals were applied to a gate electrode nearby the quantum dot. Capacitance spectroscopy on quantum dots has been performed at kHz frequencies [2]. At MHz frequencies, quantum dots can be operated as turnstiles or pumps [3].…”

Kondo effect and spin filtering in triangular artificial atoms

“…Introduction.-Submicron boxes of electrons known as "quantum dots" or "artificial atoms" have proved a fruitful playground for studying single-particle quantized states, interaction, and spin [1,2]. The role of orbital degeneracy in the formation of strongly correlated states in artificial atoms has not received the scrutiny it deserves, perhaps because orbital degeneracy is so hard to control experimentally in these systems.…”

“…Coulomb blockade peaks.-We are most interested in the case of a four-fold degenerate ground state arising from a singly-occupied Γ 3 level. 1 Such a state can be identified experimentally by looking at the height, magnetic field, and temperature dependence of the Coulomb blockade peaks. In the regime where the temperature T is smaller than the level spacing ∆ of the dot, but is still larger than any Kondo temperature or the tunneling rate ∼ 2πV 2 to the leads, the conductance around the Coulomb blockade peaks will be dominated by sequential tunneling.…”