Figure 1.

(a) Model for an Aharonov-Bohm (AB) ring with an embedded quantum dot. A quantum dot with an energy level ε₀ is connected to two external leads by tunnel couplings, V_L and V_R. Another arm of the AB ring (reference arm) and external leads are represented by a one-dimensional tight-binding model. The reference arm includes a tunnel barrier with transfer integral W. The magnetic flux Φ penetrating the ring is considered as an AB phase ϕ = 2πΦ/Φ₀ with flux quantum Φ₀ = h/e. (b) The density of states in the lead for the reduced model, ν(ε_k) in Eq. (6). ν(ε_k) oscillates with the period of ε_T, the Thouless energy for the ballistic systems. Its amplitude and phase depend on the AB phase ϕ.