Interacting resonances and antiresonances in conjugated hydrocarbons: exceptional points and bound states in the continuum.

Quantum interference dramatically modulates electron transport that provides exciting prospects for molecular electronics. We develop a holistic picture of quantum interference phenomena in molecular conductors based on conjugated hydrocarbons taking into account the interaction of resonances and antiresonances (AR). This interaction can result in the coalescence of resonances and ARs accompanied by a significant quantum transparency change.

Non-Hermitian Hamiltonians and Quantum Transport in Multi-Terminal Conductors.

We study the transport properties of multi-terminal Hermitian structures within the non-equilibrium Green's function formalism in a tight-binding approximation. We show that non-Hermitian Hamiltonians naturally appear in the description of coherent tunneling and are indispensable for the derivation of a general compact expression for the lead-to-lead transmission coefficients of an arbitrary multi-terminal system. This expression can be easily analyzed, and a robust set of conditions for finding zero and unity transmissions (even in the presence of extra electrodes) can be formulated.

Subpicosecond light pulses induced by Fano antiresonance buildup process.

We propose a simple technique of cutting short pulses out of a sharp edge input signal. The technique is based on the Fano antiresonance buildup dynamics. The output pulse duration is inverse proportional to the coupling strength to the resonator.

[Formula: see text]-symmetric interference transistor.

We present a model of the molecular transistor, operation of which is based on the interplay between two physical mechanisms, peculiar to open quantum systems that act in concert: [Formula: see text] -symmetry breaking corresponding to coalescence of resonances at the exceptional point of the molecule, connected to the leads, and Fano-Feshbach antiresonance. This switching mechanism can be realised in particular in a special class of molecules with degenerate energy levels, e.g.