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

Area of Science:

• Quantum physics
• Condensed matter physics
• Nanotechnology

Background:

• Double quantum dot systems are crucial for quantum information processing.
• Understanding quantum entropy is key to controlling quantum states.
• Previous studies often simplified system parameters, limiting accuracy.

Purpose of the Study:

• To calculate quantum entropy in a ladder-plus-Y double quantum dot system.
• To investigate the impact of various controlling parameters on quantum entropy.
• To highlight the importance of including wetting layer and transition-specific momenta.

Main Methods:

• Calculation of quantum entropy using system parameters.
• Analysis of four coherent optical fields, three tunneling components, and incoherent optical pumping.
• Inclusion of a wetting layer (WL) and transition-specific momenta.

Main Results:

• Quantum entropy is dependent on the difference in carrier occupations between the two quantum dots (QDs).
• A probe optical field decreases entropy, while a pumping field increases it.
• Removing the main tunneling component eliminates entropy; high wetting layer-quantum dot momentum increases it.

Conclusions:

• Accurate quantum entropy calculation requires considering wetting layer and specific momenta.
• Standard assumptions (uniform momentum) underestimate quantum entropy.
• The findings offer insights for optimizing quantum dot system design and control.