相关论文: Study of Low Energy Spin Rotons in the Fractional …
Resonant inelastic light scattering experiments access the low lying excitations of electron liquids in the fractional quantum Hall regime in the range $2/5 \geq \nu \geq 1/3$. Modes associated with changes in the charge and spin degrees of…
We report inelastic light scattering experiments in the fractional quantum Hall regime at filling factors $\nu\lesssim1/3$. A spin mode is observed below the Zeeman energy. The filling factor dependence of the mode energy is consistent with…
Excitation modes in the range $2/5 \geq \nu \geq 1/3$ of the fractional quantum Hall regime are observed by resonant inelastic light scattering. Spectra of spin reversed excitations suggest a structure of lowest spin-split Landau levels of…
A major obstacle toward a {\em quantitative} verification, by comparison to experiment, of the theory of the excitations of the fractional quantum Hall effect has been the lack of a proper understanding of disorder. We circumvent this…
The activation energy measured in transport experiments in the fractional Hall regime corresponds to the energy required to create a far separated particle hole pair. We calculate, for several fractional quantum Hall states, the energy gaps…
We find unexpected low energy excitations of fully spin-polarized composite-fermion ferromagnets in the fractional quantum Hall liquid, resulting from a complex interplay between a topological order manifesting through new energy levels and…
We use the dynamical structure factors of the quantum Hall states at $\nu=1/3$ and $\nu=1/2$ in the lowest Landau level to study their excitation spectrum. Using the density matrix renormalization group in combination with the…
We determine the lowest and higher order collective modes in both spin-conserving and spin-reversed sectors by calculating energy differences of the appropriate linear combinations of different levels of composite-fermion-excitons and the…
In the framework of a recently developed model of interacting composite fermions, we calculate the energy of different solid and Laughlin-type liquid phases of spin-polarized composite fermions. The liquid phases have a lower energy than…
The true nature of the lowest-energy, long-wavelength neutral excitation of the fractional quantum Hall effect has been a long outstanding problem. In this Letter, we establish that it is a two-roton bound state.
We consider the effect of interactions on electrons confined to two dimensions at Landau level filling $\nu=2$, with the specific aim to determine the range of parameters where the fully polarized state is stable. We calculate the charge…
We report on our theoretical investigations that point to the possibility of a fractional quantum Hall effect with partial spin polarization at $\nu=3/8$. The physics of the incompressible state proposed here involves p-wave pairing of…
We apply the magneto-roton theory of the fractional quantum Hall effect to study the collective excitation spectrum of rotating dipolar Fermi gases. The predicted spectrum has a finite energy gap in the long wavelength limit and a roton…
Low lying excitations of electron liquids in the fractional quantum Hall (FQH) regime are studied by resonant inelastic light scattering methods. We present here results from charge and spin excitations of FQH states in the lowest…
In this paper we study fractional quantum Hall composite fermion wavefunctions at filling fractions \nu = 2/3, 3/5, and 4/7. At each of these filling fractions, there are several possible wavefunctions with different spin polarizations,…
Charged excitons of composite fermions (CFs) are considered in the fractional quantum Hall effect. Energies of the charged CF excitons are computed at $\nu=1/3$ as a function of the size of exciton. We show that the charged CF exciton with…
The spin-excitations of a fractional quantum Hall system are evaluated within a bosonization approach. In a first step, we generalize Murthy and Shankar's Hamiltonian theory of the fractional quantum Hall effect to the case of composite…
The multitude of excitations of the fractional quantum Hall state are very accurately understood, microscopically, as excitations of composite fermions across their Landau-like $\Lambda$ levels. In particular, the dispersion of the…
The cyclotron spin-flip modes of spin unpolarized integer quantum Hall states ($\nu =2,4$) have been studied with inelastic light scattering. The energy of these modes is significantly smaller compared to the bare cyclotron gap. Second…
The low energy neutral excitations of incompressible fractional quantum Hall states are called collective modes or magnetic excitons. This work develops techniques for computing their dispersion at general filling fractions for reasonably…