Phase Evolution in a Kondo-Correlated System

• Published in: Science (American Association for the Advancement of Science) Vol. 290; no. 5492; pp. 779 - 783
• Main Authors: Ji, Yang, Heiblum, M., Sprinzak, D., Mahalu, D., Shtrikman, Hadas
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 27.10.2000; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Anvils; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Drains; Electric current; Electric potential; Electrical phases; Electronic conduction in metals and alloys; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in condensed matter; Electronic transport phenomena in thin films and low-dimensional structures; Electrons; Energy levels; Exact sciences and technology; Fermi surfaces; Gases; General theory, scattering mechanisms; Kondo effect; Lead; Magnetic fields; Measurement Techniques; Observations; Physics; Quantum dots; Scattering mechanisms and kondo effect; Vortex rings; United States; Electron correlations; Electrical conductivity; Kondo effect; Mean free path; Quantum dots; Theoretical study; Oscillations; Singlet state; Coulomb interaction; Electron gas
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.290.5492.779

We measured the phase evolution of electrons as they traverse a quantum dot (QD) formed in a two-dimensional electron gas that serves as a localized spin. The traversal phase, determined by embedding the QD in a double path electron interferometer and measuring the quantum interference of the electron wave functions manifested by conductance oscillation as a function of a weak magnetic field, evolved by π radians, a range twice as large as theoretically predicted. As the correlation weakened, a gradual transition to the familiar phase evolution of a QD was observed. The specific phase evolution observed is highly sensitive to the onset of Kondo correlation, possibly serving as an alternative fingerprint of the Kondo effect.