`
Chinese scientists harness power of ‘entanglement’ to fuel quantum engine
• Breakthrough study is the first experimental realisation of a quantum
engine with ‘entangled characteristics’, researchers said.
• The technology uses the mysterious phenomenon that allows a pair of
separated light particles to remain intimately linked, regardless of the
distance between them.
By Zhang Tong in Beijing Published: SCMP 12:00pm, 2 Jun 2024
https://archive.md/AEXjx
Researchers in China have tapped into one of the strangest phenomenon in
quantum physics to show that it could one day be used to power the next
generation of computers.
The entanglement phenomenon allows a pair of separated photons to remain
intimately linked – regardless of the distance between them – as if there is a
secret, faster-than-light communication between the two particles.
The researchers, from the Chinese Academy of Sciences’ Innovation Academy of
Precision Measurement Science and technology, said the breakthrough shows that
quantum engines can use their own entangled states as a form of fuel.
“Our study’s highlight is the first experimental realisation of a quantum
engine with entangled characteristics. [It] quantitatively verified that
entanglement can serve as a type of ‘fuel’,” said Zhou Fei, one of the
corresponding authors, on Monday.
Unlike traditional engines that operate on thermal combustion, a quantum engine
uses lasers to transition the particles between quantum states, converting
light into kinetic energy.
Zhou, along with fellow corresponding author Feng Mang and the rest of the
team, showed that the entanglement phenomenon increases the output efficiency
of quantum engines, according to the study, published on April 30 by the
journal Physical Review Letters.
Quantum engines could theoretically surpass the limits of classical
thermodynamics, potentially achieving energy conversion efficiencies of more
than 25 per cent – enough to power large-scale quantum computers and circuits.
Using ultra-cold 40Ca+ ions confined in an ion trap as the working substance
for the quantum engine, the team designed a thermodynamic cycle that converts
the external laser energy into the vibrational energy of the ions.
“We chose the entangled states of two spinning ions as the working substance,
with [their] vibrational modes acting as the load. Through precise adjustments
of laser frequency, amplitude, and duration, the ions were transitioned from
their initial pure states to highly entangled states,” Zhou said.
“We measured how well the engine works by looking at two things: conversion
efficiency, which is how many vibrations (phonons) it produces for every bit of
light (photons) it uses, and mechanical efficiency, which is how much of the
energy we can actually use compared to all the energy it puts out.”
More than 10,000 experiments revealed that higher degrees of ion entanglement
led to greater mechanical efficiency, although the conversion efficiency
remained largely unaffected by the level of entanglement.
“This indicates that quantum entanglement, despite its mysterious mechanism to
physicists, acts as a “fuel” in quantum engines,” Zhou said.
“Quantum engines are currently a very active research field, with many
theoretical analyses and studies, but very few experimental results are
provided.”
The study’s conclusions open new perspectives for the development of
micro-energy devices such as quantum motors and batteries, suggesting that the
entanglement properties of the working material can enhance the maximum
extractable energy.
According to Zhou, while quantum batteries might not store as much energy as
those used in electric vehicles, their real benefit would come from their
ability to power large-scale quantum computers and circuits.
“The future challenge lies in increasing the number of working materials
without compromising fidelity of the entanglement state, thereby enhancing
output,” he said.
--
_______________________________________________
Link mailing list
[email protected]
https://mailman.anu.edu.au/mailman/listinfo/link
