Spin-charge separation in an Aharonov-Bohm interferometer

Abstract

We study manifestations of spin-charge separation (SCS) in transport through a tunnel-coupled interacting single-channel quantum ring. We focus on the high-temperature case (temperature $T$ larger than the level spacing $\Delta$) and discuss both the classical (flux-independent) and interference contributions to the tunneling conductance of the ring in the presence of magnetic flux. We demonstrate that the SCS effects, which arise solely from the electron-electron interaction, lead to the appearance of a peculiar fine structure of the electron spectrum in the ring. Specifically, each level splits into a series of sublevels, with their spacing governed by the interaction strength. In the high-$T$ limit, the envelope of the series contains of the order of $T/\Delta$ sublevels. At the same time, SCS suppresses the tunneling width of the sublevels by a factor of $\Delta /T$. As a consequence, the classical transmission through the ring remains unchanged compared to the noninteracting case: the suppression of tunneling is compensated by the increase of the number of tunneling channels. On the other hand, the flux-dependent contribution to the conductance depends on the interaction-induced dephasing rate which is known to be parametrically increased by SCS in an infinite system. We show, however, that SCS is not effective for dephasing in the limit of weak tunneling. Moreover, generically, in the almost closed ring, the dephasing rate does not depend on the interaction strength and is determined by the tunneling coupling to the leads. In certain special symmetric cases, dephasing is further suppressed. Similar to the spinless case, the high-$T$ conductance shows, as a function of magnetic flux, a sequence of interaction-induced sharp negative peaks on top of the classical contribution.

23 pages, 9 figures (Fig. 2 and new references added, introduction extended)

References in corpus (20)

• Spin-charge separation and localization in one-dimension
• Probing spin-charge separation in a Tomonaga-Luttinger liquid
• Direct measurement of the coherence length of edge states in the Integer Quantum Hall Regime
• Finite bias visibility of the electronic Mach-Zehnder interferometer
• Spin dynamics in a one-dimensional ferromagnetic Bose gas
• Waveform measurement of charge- and spin-density wave packets in a Tomonaga-Luttinger liquid
• Green's function for magnetically incoherent interacting electrons in one dimension
• Electron transport in disordered Luttinger liquid
• Spin-Incoherent Transport in Quantum Wires
• The electron lifetime in Luttinger liquids
• Tunneling into a Luttinger liquid revisited
• Transport in a spin incoherent Luttinger liquid
• Features of spin-charge separation in the equilibrium conductance through finite rings
• Charge and energy fractionalization mechanism in one-dimensional channels
• The Interacting Mesoscopic Capacitor Out of Equilibrium
• Charge Fractionalization in Artificial Tomonaga-Luttinger Liquids with Controlled Interaction Strength
• Quantum interference and spin-charge separation in a disordered Luttinger liquid
• Spin-charge separation in transport through Luttinger liquid rings
• Effect of surface defects and few-atomic steps on the local density of states of the atomically-clean surface of topological insulator Bi${}_2$Se${}_3$
• Tunneling conductance of a mesoscopic ring with spin-orbit coupling and Tomonaga-Luttinger interaction

Cited by in corpus (4)

• Coherent spin transport through helical edge states of topological insulator
• Spin and charge transport through helical Aharonov-Bohm interferometer with strong magnetic impurity
• Tunneling Aharonov-Bohm interferometer on helical edge states
• A non-magnetic mechanism of backscattering in helical edge states