Fano-Kondo resonance versus Kondo plateau in an Aharonov-Bohm ring with an embedded quantum dot

摘要: We theoretically examine the transport through an Aharonov-Bohm ring with embedded quantum dot (QD), so-called QD interferometer, to address two controversial issues regarding shape of Coulomb peaks and measurement transmission phase shift a QD. extend previous model [B. R. Bulka P. Stefa\ifmmode \acute{n}\else \'{n}\fi{}ski, Phys. Rev. Lett. 86, 5128 (2001); W. Hofstetter, J. K\"onig, H. Schoeller, ibid. 87, 156803 (2001)] consider multiple conduction channels in external leads, $L$ $R$. introduce parameter ${p}_{\ensuremath{\alpha}}$ ($|{p}_{\ensuremath{\alpha}}|\ensuremath{\le}1$) characterize connection between arms lead $\ensuremath{\alpha}$ ($=L$, $R$), which is overlap integral modes coupled arms. First, we study conductance peak as function energy level QD, absence electron-electron interaction $U$. show asymmetric Fano resonance for $|{p}_{L,R}|=1$ case single channel leads almost symmetric Breit-Wigner $|{p}_{L,R}|l0.5$ channels. Second, Kondo effect taken into account by Bethe ansatz exact solution presence precisely evaluate at temperature $T=0$ crossover from Fano-Kondo plateau changing ${p}_{L,R}$. Our also applicable multiterminal geometry interferometer. discuss three-terminal ``double-slit experiment.'' derive analytical expression relation measured value intrinsic shift.