Bonding and anti-bonding states of artificial molecules have been realized in experiments by directly coupling two quantum dots. Without a direct coupling between two nearby quantum dots, here we show that a continuous crossover, from symmetric to anti-symmetric molecular state, can be achieved by changing the flux through a double quantum dot Aharonov-Bohm (AB) interferometer. We explicitly present the flux-dependent real-time processes of molecular-state formation. In contrast to the transport current, which has a $2π$ period, the quantum state of the DQD molecule has a $4π$ period in the AB flux.Bonding and anti-bonding states of artificial molecules have been realized in experiments by directly coupling two quantum dots. Without a direct coupling between two nearby quantum dots, here we show that a continuous crossover, from symmetric to anti-symmetric molecular state, can be achieved by changing the flux through a double quantum dot Aharonov-Bohm (AB) interferometer. We explicitly present the flux-dependent real-time processes of molecular-state formation. In contrast to the transport current, which has a $2π$ period, the quantum state of the DQD molecule has a $4π$ period in the AB flux.

arXiv:1204.5931Apr 26, 20120 citations

Intrinsic coherence dynamics and phase localization in nanoscale Aharonov-Bohm interferometers

Matisse Wei-Yuan Tu, Wei-Min Zhang, Jinshuang Jin

The nonequilibrium real-time dynamics of electron decoherence is explored in the quantum transport through the nanoscale double-dot Aharonov-Bohm interferometers. We solve the exact master equation to find the exact quantum state of the device, from which the changes of the electron coherence through the magnetic flux in the nonequilibrium transport processes is obtained explicitly. We find that the relative phase between the two charge states of the degenerate double dot localizes to $\frac{\ensuremath{\pi}}{2}$ or $\ensuremath{-}\frac{\ensuremath{\pi}}{2}$ for all different magnetic fluxes, due to decoherence. This nontrivial decoherence process can be manifested in the measurable occupation numbers.The nonequilibrium real-time dynamics of electron decoherence is explored in the quantum transport through the nanoscale double-dot Aharonov-Bohm interferometers. We solve the exact master equation to find the exact quantum state of the device, from which the changes of the electron coherence through the magnetic flux in the nonequilibrium transport processes is obtained explicitly. We find that the relative phase between the two charge states of the degenerate double dot localizes to $\frac{\ensuremath{\pi}}{2}$ or $\ensuremath{-}\frac{\ensuremath{\pi}}{2}$ for all different magnetic fluxes, due to decoherence. This nontrivial decoherence process can be manifested in the measurable occupation numbers.

Physical Review BMar 15, 201117 citations

Observation of two-particle Aharonov-Bohm interference

Izhar Neder, Nissim Ofek, Yunchul Chung +3 more

Bulletin of the American Physical SocietyMar 13, 20080 citations

2π

period, the quantum state of the DQD molecule has a

4π

period in the AB flux.