Tunable Pseudogap Kondo Effect and Quantum Phase Transitions in Aharonov-Bohm Interferometers

Journal Article · Thu Jan 01 00:00:00 EST 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.102.166806· OSTI ID:1049129

Dias Da Silva, Luis G ^[1]; Sandler, Nancy ^[2]; Simon, Pascal ^[2]; Ingersent, Kevin ^[3]; Ulloa, Sergio E ^[4]

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1. ORNL
2. Ohio University
3. University of Florida
4. Ohio University, Athens

We study two quantum dots embedded in the arms of an Aharonov-Bohm ring threaded by a magnetic flux. This system can be described by an effective one-impurity Anderson model with an energy- and flux- dependent density of states. For specific values of the flux, this density of states vanishes at the Fermi energy, yielding a controlled realization of the pseudogap Kondo effect. The conductance and trans- mission phase shifts reflect a nontrivial interplay between wave interference and interactions, providing clear signatures of quantum phase transitions between Kondo and non-Kondo ground states.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1049129
• Journal Information: Physical Review Letters, Vol. 102, Issue 16; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
GROUND STATES
INTERFEROMETERS
KONDO EFFECT
MAGNETIC FLUX
PHASE SHIFT
QUANTUM DOTS