Nav: Home

Quantum manipulation power for quantum information processing gets a boost

October 11, 2017

Traditionally, heat engines produce heat from the exchange between high-temperature and low-temperature baths. Now, imagine a heat engine that operates at quantum scale, and a system made up of an atom interacting with light (photons) confined in a reflective cavity of sub-atomic dimensions. This setup can either be at a high or low temperature, emulating the two baths found in conventional heat engines. Controlling the parameters influencing how such quantum heat engine models work could dramatically increase our power to manipulate the quantum states of the coupled atom-cavity, and accelerate our ability to process quantum information. In order for this to work, we have to find new ways of improving the efficiency of quantum heat engines. In a study published in EPJ D, Kai-Wei Sun and colleagues from Beihang University, Beijing, China, show methods for controlling the output power and efficiency of a quantum thermal engine based on the two-atom cavity. In the familiar heat engine model at macroscopic scale, referred to as the Carnot heat engine, the efficiency increases as a function of the ratio between the temperatures of the low-and high-temperature baths. By comparison, the efficiency of two-level quantum heat engines is related to the level of quantum entanglement in these two states, which are either at a low or a high temperature, and display the same probability of being occupied.

The authors found that their heat engine model only yields high efficiency and output power when the number of photons involved is small; accordingly, its efficiency and power output rapidly decrease as the number of photons increases. This implies the need to reduce the number of photons to improve the efficiency of these engines, so that we can increase the quantum manipulation power and realise quantum information processing based on atom-cavity systems.
Reference: K.W. Sun & R. Li, G.-F. Zhang (2017), A Quantum Heat Engine Based on the Tavis-Cummings Model, European Physical Journal D DOI: 10.1140/epjd/e2017-80101-3


Related Photons Articles:

What if we could teach photons to behave like electrons?
The researchers tricked photons - which are intrinsically non-magnetic - into behaving like charged electrons.
Producing single photons from a stream of single electrons
Researchers at the University of Cambridge have developed a novel technique for generating single photons, by moving single electrons in a specially designed light-emitting diode (LED).
Counting photons is now routine enough to need standards
NIST has taken a step toward enabling universal standards for single-photon detectors (SPDs), which are becoming increasingly important in science and industry.
Scientists have found out why photons flying from other galaxies do not reach the Earth
In the Universe there are extragalactic objects such as blazars, which very intensively generate a powerful gamma-ray flux, part of photons from this stream reaches the Earth, as they say, directly, and part -- are converted along the way into electrons, then again converted into photons and only then get to us.
Researchers discover new way to split and sum photons with silicon
A team of researchers at The University of Texas at Austin and the University of California, Riverside have found a way to produce a long-hypothesized phenomenon -- the transfer of energy between silicon and organic, carbon-based molecules -- in a breakthrough that has implications for information storage in quantum computing, solar energy conversion and medical imaging.
Breaking the limits: Discovery of the highest-energy photons from a gamma-ray burst
Gamma-ray bursts (GRBs) are brief and extremely powerful cosmic explosions, suddenly appearing in the sky, about once per day.
Massive photons in an artificial magnetic field
An international research collaboration from Poland, the UK and Russia has created a two-dimensional system -- a thin optical cavity filled with liquid crystal -- in which they trapped photons.
Quantum physics: Ménage à trois photon-style
When two photons become entangled, the quantum state of the first will correlate perfectly with the quantum state of the second.
Converting absorbed photons into twice as many excitons: Successful high-efficiency energy conversion with organic monolayer on gold nanocluster surface
A group of researchers from Kobe and Keio universities found that when light was exposed to the surface of a tetracene alkanethiol-modified gold nanocluster, which they developed themselves, twice as many excitons could be converted compared to the number of photons absorbed by the tetracene molecules.
Illinois researchers create first three-photon color-entangled W state
Researchers at the University of Illinois at Urbana-Champaign have constructed a quantum-mechanical state in which the colors of three photons are entangled with each other.
More Photons News and Photons Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

There's so much we've yet to explore–from outer space to the deep ocean to our own brains. This hour, Manoush goes on a journey through those uncharted places, led by TED Science Curator David Biello.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 1: Numbers
In a recent Radiolab group huddle, with coronavirus unraveling around us, the team found themselves grappling with all the numbers connected to COVID-19. Our new found 6 foot bubbles of personal space. Three percent mortality rate (or 1, or 2, or 4). 7,000 cases (now, much much more). So in the wake of that meeting, we reflect on the onslaught of numbers - what they reveal, and what they hide.  Support Radiolab today at