Observing separate spin and charge Fermi seas in a strongly correlated one-dimensional conductor

Abstract

An electron is usually considered to have only one form of kinetic energy, but could it have more, for its spin and charge, by exciting other electrons? In one dimension (1D), the physics of interacting electrons is captured well at low energies by the Tomonaga-Luttinger model, yet little has been observed experimentally beyond this linear regime. Here, we report on measurements of many-body modes in 1D gated-wires using tunnelling spectroscopy. We observe two parabolic dispersions, indicative of separate Fermi seas at high energies, associated with spin and charge excitations, together with the emergence of two additional 1D 'replica' modes that strengthen with decreasing wire length. The effective interaction strength is varied by changing the amount of 1D inter-subband screening by over 45%. Our findings demonstrate the existence of spin-charge separation in the whole energy band outside the low-energy limit of validity of the Tomonaga-Luttinger model, and also set a constraint on the validity of the newer nonlinear Tomonaga-Luttinger theory.

51 pages, 14 figures

References in corpus (9)

• Spin-charge separation and localization in one-dimension
• Universal theory of nonlinear Luttinger liquids
• Probing spin-charge separation in a Tomonaga-Luttinger liquid
• Measurements of the density-dependent many-body electron mass in 2D GaAs/AlGaAs Heterostructures
• Spin-charge separation in one-dimensional fermion systems beyond the Luttinger liquid theory
• Hierarchy of modes in an interacting system
• Spectral edge mode in interacting one-dimensional systems
• Microscopic metallic air-bridge arrays for connecting quantum devices
• Semiconductor nanodevices as a probe of strong electron correlations

Cited by in corpus (8)

• Platforms for the realization and characterization of Tomonaga-Luttinger liquids
• Finite-temperature charge and spin transport in the one-dimensional Hubbard model accounting for its global [SU (2) X SU(2) X U(1)]/Z_2^2$ symmetry
• Dynamical separation of charge and energy transport in one-dimensional Mott insulators
• Collective modes in the charge-density wave state of K${}_{0.3}$MoO${}_3$: The role of long-range Coulomb interactions revisited
• Semiconductor nanodevices as a probe of strong electron correlations
• Decoupling of the many-body effects from the electron mass in GaAs by means of reduced dimensionality
• Bosonization in $R$-paraparticle Luttinger models
• Dominant end-tunneling effect in two distinct Luttinger liquids coexisting in one quantum wire