Resistively-detected NMR lineshapes in a quasi-one dimensional electron system

Abstract

We observe variation in the resistively-detected nuclear magnetic resonance (RDNMR) lineshapes in quantum Hall breakdown. The breakdown is locally occurred in a gate-defined quantum point contact (QPC) region. Of particular interest is the observation of a dispersive lineshape occured when the bulk 2D electron gas (2DEG) is set to ${\nu }_{\mathrm{b}}=2$ and the QPC filling factor to the vicinity of ${\nu }_{\mathrm{QPC}}=1$, strikingly resemble the dispersive lineshape observed on a 2D quantum Hall state. This previously unobserved lineshape in a QPC points to simultaneous occurrence of two hyperfine-mediated spin flip-flop processes within the QPC. Those events give rise to two different sets of nuclei polarized in the opposite direction and positioned at a separate region with different degree of electronic polarizations.

arXiv commentAccepted as a rapid communication in PRB

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Cited by in corpus (6)

• Shot Noise in Mesoscopic Systems: from Single Particles to Quantum Liquids
• Probing strain modulation in a gate-defined one dimensional electron system
• Dynamic nuclear polarization at high Landau levels in a quantum point contact
• Two-step breakdown of a local v = 1 quantum Hall state
• Dipole-like dynamical nuclear spin polarization around a quantum point contact
• Proposal for a solid-state magnetoresistive Larmor quantum clock