Interference and interaction effects in multilevel quantum dots - art. no.125309

Using renormalization group techniques, we study spectral and transport pro perties of a spinless interacting quantum dot consisting of two levels coup led to metallic reservoirs. For strong Coulomb repulsion U and an applied A haronov-Bohm phase phi, we find a large direct tunnel splitting \Delta\simi lar to(Gamma/pi)\cos(phi /2)\ln(U/omega (c)) between the levels of the orde r of the level broadening Gamma. As a consequence we discover a many-body r esonance in the spectral density that can be measured via the absorption po wer. Furthermore, for phi = pi we show that the system can be tuned into an effective Anderson model with spin-dependent tunneling.