  Charge sensing in quantum-dot structures is studied by an exactly solvable
reduced model and numerical density-matrix renormalization group methods.
Charge sensing is characterized by the repeated cycling of the occupation of
current-carrying states due to the capacitive coupling to trap states which are
weakly coupled to the leads. In agreement with recent experiments, it results
in a variety of characteristic behaviors ranging from asymmetric
Coulomb-blockade peaks to sawtooth- and dome-like structures. Temperature
introduces distinct asymmetric smearing of these features and correlations in
the conductance provide a fingerprint of charge-sensing behavior.
