238 research outputs found
Entanglement dynamics of photon pairs emitted from quantum dot
We present a model to derive the state of the photon pairs generated by the
biexciton cascade decay of a self-assembled quantum dot, which agrees well with
the experimental result. Furthermore we calculate the concurrence and
entanglement sudden death is found in this system with temperature increasing,
which prevents quantum dot emits entangled photon pairs at a high temperature.
The relationship between the fine structure splitting and the sudden death
temperature is provided too
Phase Compensation Enhancement of Photon Pair Entanglement Generated from Biexciton Decays in Quantum Dots
Exciton fine-structure splittings within quantum dots introduce phase
differences between the two biexciton decay paths that greatly reduce the
entanglement of photon pairs generated via biexciton recombination. We analyze
this problem in the frequency domain and propose a practicable method to
compensate the phase difference by inserting a spatial light modulator, which
substantially improves the entanglement of the photon pairs without any loss.Comment: 4 pages, 3 figure
Revisiting Bohr's principle of complementarity using a quantum device
Bohr's principle of complementarity lies at the central place of quantum
mechanics, according to which the light is chosen to behave as a wave or
particles, depending on some exclusive detecting devices. Later, intermediate
cases are found, but the total information of the wave-like and particle-like
behaviors are limited by some inequalities. One of them is Englert-Greenberger
(EG) duality relation. This relation has been demonstrated by many experiments
with the classical detecting devices. Here by introducing a quantum detecting
device into the experiment, we find the limit of the duality relation is
exceeded due to the interference between the photon's wave and particle
properties. However, our further results show that this experiment still obey a
generalized EG duality relation. The introducing of the quantum device causes
the new phenomenon, provides an generalization of the complementarity
principle, and opens new insights into our understanding of quantum mechanics.Comment: 5 pages, 4 figure
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