A robust, two-ion quantum logic gate that operates in a microsecond is designed

March 24, 2017

The theory group led by Gonzalo Muga of the UPV/EHU's Department of Physical Chemistry has teamed up with the experimental group of the National Institute of Standards and Technology in Boulder, United States, led by David Wineland, the 2012 Nobel Physics Laureate, to design a two-ion, robust, ultrarapid quantum logic gate capable of functioning in less than a microsecond. This study was published in February in the journal Physical Review A.

This theoretical research explores what could be achieved beyond current technological limitations to further motivate experimental progress. Together with qubits (the quantum version of the 0/1 bit), are the basic components of a quantum computer. They need to be fast not only to speed up the calculations, but also to minimize harmful interactions with environmental noise.

In the 1980s, Richard Feynman proposed a "quantum computer" that would outperform ordinary computers by exploiting quantum properties such as the possibility of calculating several paths in parallel. Over 30 years later, it is still difficult to realize technologically, because the useful quantum behaviour of atoms is easily destroyed by noise and unwanted interactions. Yet researchers have made progress with new architectures to control physical systems so that they behave as expected.

One of the most advanced architectures uses trapped ions, which can be isolated and handled with great precision using lasers and electrodes to produce qubits and . Two-qubit gates, such as the one examined in the study, may be useful for other applications of quantum technology, such as secure communications. This makes them particularly valuable gates, but designing and manufacturing them is challenging. High accuracy and speed are crucial to performing arbitrary computations in a fault-tolerant way.

According to Gonzalo Muga, this work "is another step forward among the many that have yet to be taken" towards attaining a quantum computer, "capable of making calculations that cannot be tackled by a traditional computer."

Explore further: The quantum computers of the future will work equally well with encrypted and unencrypted inputs

More information: M. Palmero et al. Fast phase gates with trapped ions, Physical Review A (2017). DOI: 10.1103/PhysRevA.95.022328

Related Stories

Physicists demonstrate a quantum Fredkin gate

March 25, 2016

Researchers from Griffith University and the University of Queensland have overcome one of the key challenges to quantum computing by simplifying a complex quantum logic operation. They demonstrated this by experimentally ...

Stable quantum bits can be made from complex molecules

November 10, 2016

Quantum computing is about to get more complex. Researchers have evidence that large molecules made of nickel and chromium can store and process information in the same way bytes do for digital computers. The researchers ...

Paving the way for a faster quantum computer

August 11, 2015

A team of physicists from the University of Vienna and the Austrian Academy of Sciences have demonstrated a new quantum computation scheme in which operations occur without a well-defined order. The researchers led by Philip ...

Tracking the flow of quantum information

November 17, 2016

If objects in motion are like rainwater flowing through a gutter and landing in a puddle, then quantum objects in motion are like rainwater that might end up in a bunch of puddles, all at once. Figuring out where quantum ...

Recommended for you

0 comments

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.