(Fig.1) Quantum memory is impractical, losing too many photons or quantum information
The 14th, 18th paragraphs of this hyped news (4/16/2024) about (still-impractical) quantum memory say
"A 'quantum dot' produced (non-entangled) photons (= just weak light ), which were then passed to a quantum memory system that stored the photons within a cloud of rubidium atoms."
"The team will (= still do nothing ) now look to improve the system,... improving how long the photons can be stored (= today's impractical quantum memory can retain informaion for only too short time )"
↑ This research paper ↓
p.1-abstract says "We store single photons from an indium arsenide quantum dot in a high-bandwidth rubidium vapor–based quantum memory, with a total internal memory efficiency of 12.9 % (= losing 88.1% of all photons or stored information )."
This p.2-Efficiency (η) says
"The memory efficiency is ratio of probability of detecting the output photon
to that of the input photon ( this p.2-right-last )"
↑ This means even this recent quantum memory (= rubidium atom storing input photon quantum information as excited energy ) lost 87% of all the input photons or quantum inofrmation (= memory efficienty is just about 13% ).
So today's quantum memories losing almost all stored quantum information or photons with extremely low stroing efficienty ( this p.4-left-results. Their storing time is also impractically too short, only 800ps, this-p.3-right-3rd-paragraph ) is completely useless (forever).
Feel free to link to this site.
