Spin Fluctuations in the 0.7 Anomaly in Quantum Point Contacts

Dennis H. Schimmel, Benedikt Bruognolo, and Jan von Delft
Phys. Rev. Lett. 119, 196401 – Published 7 November 2017
PDFHTMLExport Citation

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.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 9 March 2017

DOI:https://doi.org/10.1103/PhysRevLett.119.196401

© 2017 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Dennis H. Schimmel1, Benedikt Bruognolo1,2, and Jan von Delft1

  • 1Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität, Theresienstraße 37, 80333 Munich, Germany
  • 2Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching, Germany

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 119, Iss. 19 — 10 November 2017

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×