Quantum Computer Measures Energy in Molecular Hydrogen

[bananas]

http://www.physorg.com/news182181821.html

Quantum Computer Measures Energy in Molecular Hydrogen
January 10, 2010 by Miranda Marquit Hydrogen Atom

(PhysOrg.com) -- When it comes to measuring the properties of molecules, scientists often rely on using approximation, since quantum mechanics cannot be exactly apply to complicated situations without the use of a quantum computer. In an effort to ensure that no natural behaviors are missed, and for other purposes, scientists around the world have been working on quantum computers for decades.

And one has been built -- and used to measure molecular hydrogen.

Scientists at the University of Queensland in Brisbane, Australia, and at Harvard University, in the U.S., have built a small quantum computer capable of handling calculations on groupings of atoms that are larger than previously used. The approach to molecular simulation is described in this week's issue of Nature Chemistry.

The University of Queensland offers this in a press release on the implications of the project:

<snip>

Here's the press release:

http://www.uq.edu.au/news/index.html?article=20368

Published: 07 January 2010

UQ’s quantum computers make light work of Harvard's chemistry

UQ physicists and Harvard chemists have teamed up to build a quantum computer that could have profound implications for wider science.

Professor Andrew White and colleagues from UQ's School of Mathematics and Physics, teamed up with researchers from Harvard University, led by Professor Alán Aspuru-Guzik, to tackle the problem of applying quantum mechanics to fields such as chemistry and biology.

“Physicists have a problem,” Professor White said.

“They have an outstandingly successful theory of nature at the small scale – quantum mechanics – but have been unable to apply it exactly to situations more complicated than, say, four or five atoms.

“But now we have done exactly that by building a small quantum computer and used it to calculate the precise energy of molecular hydrogen."

<snip>

[Recursion]

1. I wonder what the energy/time indeterminancy relationship does to this

Q Mech was decades ago for me, but IIRC energy and time have the same uncertainty relationship as position and momentum. So the more accurately they measure the atom's energy, the less accurately they know at what time they're measuring it.

[byronius]

2. Here comes the asymptote.

[NNadir]

3. One of the statements here will come as a huge surprise to all of the world's molecular modelers.

Specifically it's this one:

“They have an outstandingly successful theory of nature at the small scale – quantum mechanics – but have been unable to apply it exactly to situations more complicated than, say, four or five atoms.

Maybe Professor White would like to be the one to tell Raold Hoffman that he should give his Nobel Prize back.

Hoffman seems like a wonderful guy, with a great sense of humor, a Gene Wilder kind of personality, at least to a casual observer. I'm sure he'd get a great laugh out of that one.

And someone should tell Howard Zimmerman to unwrite his book, now older than Amory Lovins' reports that "nuclear power is dead.":

http://pubs.acs.org/doi/abs/10.1021/ed054pA300.2

The hedge word is, I guess, "exactly," but it's trivial. People have been using self consistent fields and similar approaches, with great success, by the way, for decades.