Magnetic States in Prismatic Core Multishell Nanowires

Abstract

We study the electronic states of core multishell semiconductor nanowires, including the effect of strong magnetic fields. We show that the multishell overgrowth of a free-standing nanowire, together with the prismatic symmetry of the substrate, may induce quantum confinement of carriers in a set of quasi-1D quantum channels corresponding to the nanowire edges. Localization and interchannel tunnel coupling are controlled by the curvature at the edges and the diameter of the underlying nanowire. We also show that a magnetic field may induce either Aharonov-Bohm oscillations of the energy levels in the axial configuration, or a dimensional transition of the quantum states from quasi-1D to Landau levels for fields normal to the axis. Explicit predictions are given for nanostructures based on GaAs, InAs, and InGaN with different symmetries.

Conductance oscillations of core-shell nanowires in transversal magnetic fields

“…Low-energy electrons may be found around two channels along the CSN axis where the radial component of the field vanishes by changing sign. Carriers on both sides of the lines are deflected towards opposite directions and thus confined into so called snaking states [19][20][21][22]. Higher energy electrons start to occupy Landau states and form cyclotron orbits localized in the areas where the radial component of the field takes maximal values.…”

Fundamental limits in the external quantum efficiency of single nanowire solar cells

“…Their increasing importance in both science and engineering is a consequence of the great number of fundamental experiments and applications they enable. [1][2][3][4][5][6][7][8] In the recent years, an increasing interest in the use of nanowires for solar cell applications has been observed. 9 The set point for this was the realization that radial nanowire p(i)n junctions offer a significant advantage with respect to the planar counterparts, as they allow to orthogonalize the light absorption with the carrier separation in the device.…”

“…10 Additionally, the possibility of combining lattice mismatched materials in one same device opens great perspectives in the area of multiple junction photovoltaics. 7,8,11,12 Recently nanowire based solar cells with both axial and radial p-n junctions have been demonstrated in various material systems. [13][14][15][16] Even though the ultimate device should consist in a forest of vertical nanowires, to date many experiments are carried out on single nanowire devices that are placed on a substrate with the light incident perpendicular to the substrate surface.…”

Free standing modulation doped core–shell GaAs/AlGaAs hetero‐nanowires

“…The whole structure is covered with a thin layer of GaAs to protect the AlGaAs shell. Electrons are expected to accumulate at the GaAs/AlGaAs interface leading to the formation of six planes with 2DES as well as 1D channels in the corners for thick enough cores [8]. The conduction band profile and the electron density along the red line in (a) calculated using the nextnano 3 simulation package [9] for a core thickness of 100 nm are presented in Fig.…”