Mesoscopic Coulomb Blockade in One-Channel Quantum Dots

Signatures of “mesoscopic Coulomb blockade” are reported for quantum dots with one fully transmitting point-contact lead; $T_1=1,T_2\ll 1$. Unlike the Coulomb blockade (CB) in weak-tunneling devices $(T_1,T_2\ll 1)$, one-channel CB is a mesoscopic effect requiring quantum coherence. Several distinctive features of mesoscopic CB are observed, including a reduction in CB upon breaking time-reversal symmetry with a magnetic field, relatively large fluctuations of peak position as a function of magnetic field, and strong temperature dependence on the scale of the quantum level spacing.