Entanglement in ladder-plus-Y double quantum dot structure via entropy.

Quantum entropy in a ladder-plus-Y double quantum dot system was calculated. The controlling parameters that are examined are four coherent optical fields, three tunneling components, and incoherent optical pumping. This work differs from others by the inclusion of a wetting layer (WL) and the calculation of momenta for each transition. The results showed that the entropy depends on the difference between the carrier occupations in the states of these two quantum dots (QDs). It is also shown that the probe optical field reduces the entropy, while the pumping field increases it. Turning off the main tunneling component removes the entropy, while high WL-QD momentum increases the entropy. Taking the same value of momentum for all transitions (the case of other works) underestimates the entropy.