Spin Fluctuations in the 0.7 Anomaly in Quantum Point Contacts

Schimmel, Dennis H.; Bruognolo, Benedikt und Delft, Jan von (2017): Spin Fluctuations in the 0.7 Anomaly in Quantum Point Contacts. In: Physical Review Letters, Bd. 119, Nr. 19, 196401

Abstract

It has been argued that the 0.7 anomaly in quantum point contacts (QPCs) is due to an enhanced density of states at the top of the QPC barrier (the van Hove ridge), which strongly enhances the effects of interactions. Here, we analyze their effect on dynamical quantities. We find that they pin the van Hove ridge to the chemical potential when the QPC is subopen, cause a temperature dependence for the linear conductance that qualitatively agrees with experiments, strongly enhance the magnitude of the dynamical spin susceptibility, and significantly lengthen the QPC traversal time. We conclude that electrons traverse the QPC via a slowly fluctuating spin structure of finite spatial extent.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Fakultätsübergreifende Einrichtungen: Center for NanoScience (CENS)
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik ; 500 Naturwissenschaften und Mathematik > 500 Naturwissenschaften
• ISSN: 0031-9007
• Sprache: Englisch