Hierarchy of modes in an interacting one-dimensional system
Research output: Contribution to journal › Article › peer-review
Authors
Colleges, School and Institutes
External organisations
- Cavendish Laboratory
Abstract
Studying interacting fermions in one dimension at high energy, we find a hierarchy in the spectral weights of the excitations theoretically, and we observe evidence for second-level excitations experimentally. Diagonalizing a model of fermions (without spin), we show that levels of the hierarchy are separated by powers of R2/L2, where R is a length scale related to interactions and L is the system length. The first-level (strongest) excitations form a mode with parabolic dispersion, like that of a renormalized single particle. The second-level excitations produce a singular power-law line shape to the first-level mode and multiple power laws at the spectral edge. We measure momentum-resolved tunneling of electrons (fermions with spin) from or to a wire formed within a GaAs heterostructure, which shows parabolic dispersion of the first-level mode and well-resolved spin-charge separation at low energy with appreciable interaction strength. We find structure resembling the second-level excitations, which dies away quite rapidly at high momentum.
Details
Original language | English |
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Article number | 196401 |
Number of pages | 5 |
Journal | Physical Review Letters |
Volume | 114 |
Publication status | Published - 11 May 2015 |