Feeds

Micro-drum acts as quantum memory

NIST puts qubits in a spin

Build a business case: developing custom apps

Memory is one of the difficult bits of quantum computing. For example, while the polarisation of a photon encodes a quantum state, it's very difficult to get photons to stay where they're put.

A group of researchers from JILA – a joint institute between the University of Colorado and the National Institute of Standards and Technology – has demonstrated a different approach to capturing quantum states in memory: they're using a microscopic spinning platter to do the job.

At the moment, it's not very accurate: the spinning drum captured the vertical and horizontal positions of a microwave signal at a point in time (the quantum state they were trying to capture), but that state could only be retrieved with 65 percent accuracy.

The micro-drum was created by NIST in 2011. Because it's embedded in a resonant circuit, the drum is able to beat at different frequencies. That means the electrical energy in the microwaves can be captured as mechanical energy as a phonon (a unit of vibration).

NIST micro-drum

NIST's micro-drum and circuit (colorised image)

To get this interaction happening at the quantum level, the researchers had to cool the drum to its lowest-possible energy state, at which point it has less than one quantum of its own energy. The microwaves used to cool the drum to its ground state also transfer information about the their quantum states to the drum, in the form of a temporary state beating at the received frequency.

The researchers also found a way to turn the microwave-drum interaction on and off, based on the intensity of the microwave tone.

If the researchers can improve the performance of the quantum memory, they'll end up with something that's compatible – both in size and in the fabrication techniques used – with devices that NIST uses as qubits.

NIST says in practice, the micro-drum is somewhat like the delay-line memory used in early computers like NIST's SEAC of the 1950s, in which computation values were temporarily stored as acoustic waves travelling down a column of a fluid like mercury.

The NIST research is to published in Nature and its announcement is here. ®

Bootnote: The researchers note that the drum is actually a quasi-quantum memory: its beat is a classical system, but in a quantum-noisy environment. This author isn't physicist enough to completely understand the distinction. ®

Securing Web Applications Made Simple and Scalable

More from The Register

next story
Asteroid's DINO KILLING SPREE just bad luck – boffins
Sauricide WASN'T inevitable, reckon scientists
BEST BATTERY EVER: All lithium, all the time, plus a dash of carbon nano-stuff
We have found the Holy Grail (of batteries) - boffins
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
Famous 'Dish' radio telescope to be emptied in budget crisis: CSIRO
Radio astronomy suffering to protect Square Kilometre Array
Bad back? Show some spine and stop popping paracetamol
Study finds common pain-killer doesn't reduce pain or shorten recovery
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.