Zero-Momentum Cyclotron Spin-Flip Mode in a Spin-Unpolarized Quantum Hall System

TL;DR

This paper investigates the zero-momentum cyclotron spin-flip excitation in a spin-unpolarized quantum Hall system, revealing a significant negative exchange shift and identifying it as the lowest-energy excitation mode.

Contribution

It provides a theoretical calculation of the excitation energy including Coulomb corrections, aligning with experimental results and highlighting the mode's energetic significance.

Findings

Negative exchange shift relative to the cyclotron gap

Energy shift independent of magnetic field at V=2

Identification of the mode as the lowest-energy excitation

Abstract

We report on a study of the zero-momentum cyclotron spin-flip excitation in the V=2 quantum Hall regime. Using the excitonic representation the excitation energy is calculated up to the second order Coulomb corrections. A considerable negative exchange shift relative to the cyclotron gap is established for cyclotron spin-flip excitations in the the spin-unpolarized electronic system. Under these conditions this type of states presents the {\it lowest-energy} excitations. For a fixed filling factor V=2 the energy shift is independent of the magnetic field which is in agreement with recent experimental observations.