Observation of soft magnetorotons in bilayer quantum Hall ferromagnets
arXiv:cond-mat/0301295 · doi:10.1103/PhysRevLett.90.236802
Abstract
Inelastic light scattering measurements of low-lying collective excitations of electron double layers in the quantum Hall state at total filling nu_T=1 reveal a deep magnetoroton in the dispersion of charge-density excitations across the tunneling gap. The roton softens and sharpens markedly when the phase boundary for transitions to highly correlated compressible states is approached. The findings are interpreted with Hartree-Fock evaluations that link soft magnetorotons to enhanced excitonic Coulomb interactions and to quantum phase transitions in the ferromagnetic bilayers.
arXiv commentReVTeX4, 4 pages, 4 EPS figures
References in corpus (10)
- Evidence for a Goldstone Mode in a Double Layer Quantum Hall System
- Distribution of occupation numbers in finite Fermi-systems and role of interaction in chaos and thermalization
- Observation of a Linearly Dispersing Collective Mode in a Quantum Hall Ferromagnet
- Observation of Quantized Hall Drag in a Strongly Correlated Bilayer Electron System
- Double-layer quantum Hall antiferromagnetism at filling fraction nu=2/(odd integer)
- Josephson Effect Without Superconductivity: Realization in Quantum Hall Bilayers
- Spontaneous Interlayer Coherence in Double-Layer Quantum Hall Systems: Symmetry Breaking Interactions, In-Plane Fields and Phase Solitons
- Bias-voltage induced phase-transition in bilayer quantum Hall ferromagnets
- Magnetoplasmon Excitations and Spin Density Instabilities in an Integer Quantum Hall System with a Tilted Magnetic Field
- Finite Temperature Behavior of the Quantum Hall Effect in Bilayer Electron Systems
Cited by in corpus (12)
- Gate-Tuned Spontaneous Exciton Insulator in Double-Quantum Wells
- Entanglement Spectrum and Entanglement Thermodynamics of Quantum Hall Bilayers at nu=1
- Excitonic Superfluid to pseudo-spin density wave transition in bilayer quantum Hall systems
- Spontaneous Symmetry Breaking and Exotic Quantum Order in Integer Quantum Hall Systems under a Tilted Magnetic Field
- Observation of collapse of pseudospin order in bilayer quantum Hall ferromagnets
- Ultrafast Dynamic Control of Spin and Charge Density Oscillations in a GaAs Quantum Well
- Collective electronic excitation in a trapped ensemble of photogenerated dipolar excitons and free holes revealed by inelastic light scattering
- Coherent exciton transport in semiconductors
- Metamorphosis of a Quantum Hall Bilayer State into a Composite Fermion Metal
- Noise spectroscopy and interlayer phase-coherence in bilayer quantum Hall systems
- Soft Magnetorotons and Broken-Symmetry States in Bilayer Quantum Hall Ferromagnets
- Spectroscopy of soft modes and quantum phase transitions in coupled electron bilayers