Binding of two-electron metastable states in semiconductor quantum dots under a magnetic field

GARAGIOLA, MARIANO; PONT, FEDERICO M.; OSENDA, OMAR

JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

IOP PUBLISHING LTD

Año: 2018

0953-4075

Abstract. Applying a strong enough magnetic field results in the binding of few electrons resonant states. The mechanism was proposed many years ago but its verification in laboratory conditions is far more recent. In this work we study the binding of two-electron resonant states. The electrons are confined in a cylindrical quantum dot which is embedded in a semiconductor wire. The geometry considered is similar to the one used in actual experimental setups. The low energy two-electron spectrum is calculated numerically from an effective mass approximation Hamiltonian modelling the system. Methods for binding thresholds calculations in systems with one- and two-electrons are thoroughly studied, in particular, we use quantum information quantities to asses when the strong lateral confinement approximation can be usedto obtain reliable low-energy spectra. For reasons of simplicity, only cases without bound states in the absence of external field are consider. Under this conditions, the binding threshold for the one-electron case is given by the lowest Landau energy level. Moreover, the energy of the one-electron bounded resonance can be used to obtain the two-electron binding threshold. It is shown that for realistic values of the two-electronmodel parameters it is feasible to bind resonances with field strengths of few tens of Teslas.