Saturday, April 07, 2012

Quantum computer in a diamond

Technical: Speed up your MathJax \(\rm\LaTeX\) by a second per page, at least in Windows. Download these zipped OTF fonts, unzip them, and for each of the 22 OTF files, right-click Properties/General and "unblock". Then choose all the 22 OTF files and install them. It will display the same maths you're used from the web, but using your local copy of the fonts. (These are not STIX fonts which I consider uglier but the very same fonts you're used to.)
TGDaily and dozens of other sources inform about some progress done at the USC in California by Prof Daniel Lidar and his lab.

They claim to protect their computer's two qubits from decoherence by a nice material: diamond.

One qubit is the nuclear spin of one impurity in the diamond; another qubit is carried by an electron in another impurity inside the diamond. Microwave pulses are said to constantly switch the direction of the electron's spin. The decoherence time for the nuclear spin is said to be in milliseconds which seems long.

The experimenters claim to have reproduced Grover's algorithm, a fast search through an unsorted database that I once described in an undergraduate journal "Pictures of Yellow Roses" back in Prague. Well, I am not sure how useful 2 qubits may be to search through a database but it's plausible that their approach could generalize to functional quantum computers...

The research was published in Nature.


  1. Lubos, if you're so smart, why do you live in the Czech Republic?

  2. Because it's my homeland, isn't it?

    I was born here, not on Mars or in Kenya. Regardless of their aptitude, people may be born in various countries of the world with various nonzero probabilities. And it has never been my intent to "emigrate", not even during communism against which I fought.

    The density of smart people in Czechia is about the same as it is e.g. in the U.S.