UQ Physics boosts the signal

May 10, 2010, University of Queensland

(PhysOrg.com) -- University of Queensland physicists have demonstrated a novel solution to the problem of information degradation when amplifying signals at the quantum information level.

Researchers from UQ School of Mathematics and Physics and Griffith University have published their results in .

Traditionally amplifiers take an input and multiply its size by a set amount, for example, music at a live gig might be doubled in volume through a PA system.

In current applications using optical fibres, light carrying information can be amplified many times without serious degradation.

In contrast, when we get down to the level of fundamental particles such as atoms or photons, the rules of that govern the behavior of such particles, prohibit ideal amplification.

Professor Tim Ralph's team has found that it is possible to make a device that performs ideal amplification at this level, as long as it does not always work.

No one had previously noticed that quantum systems could be amplified in this way, so this discovery increases our knowledge of how quantum systems work.

“The important thing is that an indicator on the device tells you when it has worked properly,” said Professor Ralph from UQ's ARC Centre for Quantum Computer Technology.

“It turns out that having a device that works reliably sometimes is sufficient to counteract the detrimental effects of losses in applications like .”

Using this device, the team has now demonstrated this noiseless quantum amplifier in a set of experiments in which light beams at the quantum level were amplified without degradation.

The team were also able to show that their noiseless amplifier could increase the mysterious quantum property "entanglement".

“Entanglement is a special sort correlation between parties. When we amplify the light we increase the strength of the correlation,” Professor Ralph said.

“For many quantum technologies, like quantum teleportation, the starting point is to share entanglement - our amplifier makes it easier to share.

"We expect that practical techniques for improving security of communications will be one thing to emerge from this work.”

Explore further: Quantum technologies move a step closer with the demonstration of an 'entanglement' filter

Related Stories

Physicist proposes method to teleport energy

February 5, 2010

(PhysOrg.com) -- Using the same quantum principles that enable the teleportation of information, a new proposal shows how it may be possible to teleport energy. By exploiting the quantum energy fluctuations in entangled particles, ...

A solid case of entanglement

January 11, 2010

Physicists have finally managed to demonstrate quantum entanglement of spatially separated electrons in solid state circuitry.

Recommended for you

X-rays reveal chirality in swirling electric vortices

January 16, 2018

Scientists used spiraling X-rays at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) to observe, for the first time, a property that gives handedness to swirling electric patterns – dubbed ...

Slow 'hot electrons' could improve solar cell efficiency

January 16, 2018

Photons with energy higher than the band gap of the semiconductor absorbing them give rise to what are known as hot electrons. The extra energy in respect to the band gap is lost very fast, as it is converted into heat and ...

Quan­tum physics turned into tan­gi­ble re­al­ity

January 16, 2018

ETH physicists have developed a silicon wafer that behaves like a topological insulator when stimulated using ultrasound. They have thereby succeeded in turning an abstract theoretical concept into a macroscopic product.

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

bluehigh
1 / 5 (2) May 11, 2010
In between reading a dictionary and relying on Wikipedia, University of Queensland pseudo academics publish unverifed speculation. More scientists in the money shower.

Skeptic_Heretic
1 / 5 (1) May 11, 2010
If this amplifier works as they describe it would be 100% noiseless only when it wasn't 100% noise. There's nothing quantum about it. This is a digital ballastless amplifier.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.