Electron pairing in nanostructures driven by an oscillating field

It is shown theoretically that the confinement of an electron at a repulsive potential can exist in nanostructures subjected to a strong high-frequency electromagnetic field. As a result of the confinement, the metastable bound electron state of the repulsive potential appears. This effect can lead, particularly, to electron pairing in nanostructures containing conduction electrons with different effective masses.

Figure 1

The 1D electron problem: (a) scheme of genesis of the two-barrier potential $U_0\left(x^{\prime }\right)$; (b) the potential (4) plotted for different $\lambda =x_0/a$; (c) the electron trajectory corresponding to the bound state (the heavy red line) confined near the peak of the repulsive potential $U\left(x\right)$; (d) the metastable bound state with the wave function ${\psi }_0$ and the energy ${\varepsilon }_0$, which can decay due to the tunneling effect and the field absorption.

Figure 2

The 2D repulsive Coulomb potential renormalized by an electromagnetic field with different polarizations: (a) linear polarization along the $x$ axis; (b) circular polarization in the $x,y$ plane.

Figure 3

The two-layer quantum well irradiated by a circularly polarized electromagnetic wave: (a) sketch of the system under consideration; (b) the renormalized Coulomb potential (10) plotted for ${\overline{\rho }}_0/d=4$.