Abstract
We study a model proposed recently in which a small quantum dot is coupled symmetrically to several large quantum dots characterized by a charging energy . Even if is much smaller than the Kondo temperature , the long-ranged interactions destabilize the single-channel Kondo effect and induce a flow towards a multichannel Kondo fixed point associated with a rise of the impurity entropy with decreasing temperature. Such an “uphill flow” implies a negative impurity specific heat, in contrast with all systems with local interactions. An exact solution found for a large number of channels allows us to capture this physics and to predict transport properties.
- Received 12 November 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.216601
©2004 American Physical Society