Spin-Resolved Quantum Scars in Confined Spin-Coupled Two-Dimensional Electron Gas

Abstract

Quantum scars refer to an enhanced localization of the probability density of states in the spectral region with a high energy level density. Scars are discussed for a number of confined pure and impurity-doped electronic systems. Here, we studied the role of spin on quantum scarring for a generic system, namely a semiconductor-heterostructure-based two-dimensional electron gas subjected to a confining potential, an external magnetic field, and a Rashba-type spin-orbit coupling. Calculating the high energy spectrum for each spin channel and corresponding states, as well as employing statistical methods known for the spinless case, we showed that spin-dependent scarring occurs in a spin-coupled electronic system. Scars can be spin mixed or spin polarized and may be detected via transport measurements or spin-polarized scanning tunneling spectroscopy.

Controllable Spin‐Split Phantom Scars in Quantum Dots

“…For an insight it is beneficial to analyze the spin‐resolved spectra. [ 44,55 ] Here, the magnetic field was varied from 60 to $$940\,\text{mT}$$, and three values for the SOC parameter α were chosen, 7, 14, and $$22\,\,\mathrm{meV}{\AA}$$. Even with SOC, scars are found.…”

“…Generally, one may have scattering in the spin channel only (for instance, scattering from a magnetic domain wall [ 43 ] ) and yet act on the charge channel. For a system hosting a spin‐orbital coupling, scalar impurity scattering can lead to spin‐dependent scarring [ 44 ] and mix the spin channels for a magnetic system. Another aspect to be addressed here is the possibility of teleportation of scarred states (as quantified below) to a localized region which for itself does not exhibit scarring.…”

Controllable quantum scars induced by spin–orbit couplings in quantum dots

“…Its corresponding classical Hamiltonian leads to nonlinearity in Hamilton’s equation and it is possible to drive chaotic dynamics [ 36 – 38 ]. Exploring quantum scars induced by SOCs could thus offer an intriguing avenue [ 39 ].…”

“…Comparing with the impurities induced quantum scars, the scars induced by SOCs are more tunable, less random, exist at low-energy levels, and spin-involved. We thus expect the corresponding measurements to be more convenient by scanning tunneling spectroscopy [ 69 , 70 ], scanning gate microscopy [ 71 ], scanning the NMR experiment [ 72 – 74 ] and the spin-dependent transport [ 39 , 75 – 77 ].…”