Scheme for coherently quenching resonant current in a three-level quantum dot energy level mixerScheme for coherently quenching resonant current in a three-level quantum dot energy level mixer
Faculty of Sciences. Physics
Condensed Matter Theory
Physica status solidi: C: conferences and critical reviews. - Berlin
6(2009):4, p. 940-943
University of Antwerp
We outline a scheme to create a dark state by three-level mixing that is potentially a useful tool for quantum coherent transport. Magnetic-field-induced intra-dot level mixing can lead to rich quantum superposition phenomena between three approaching single-particle states in a quantum dot when probed by the ground state of an adjacent weakly coupled quantum dot in the single-electron resonant tunnelling regime. The mixing relies on non-negligible anharmonicity and anisotropy in confining potentials of realistic quantum dots. Anti-crossing and transfer of strengths between resonances can be understood with a simple coherent level mixing model. Superposition can lead to the formation of a dark state by complete cancellation of an otherwise strong resonance. This is an all-electrical analogue of coherent population trapping seen in three-level-systems from quantum and atom optics.