Physics Nobel prize for quantum computing

Guess many of the professional bloggers have already posted about the very recent announcement on the Nobel prize in physics by the Royal Swedish Academy. Serge Haroche of Collège de France and École Normale Supérieure, Paris and David J. Wineland of NIST, Boulder, Colorado have been awarded the prize “for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems”.

First of all we can see that all the predictions failed this time (see my previous post). And I must admit I knew one of the winners, who is Prof. Haroche. I delivered a talk on circuit quantum electrodynamics (cQED) in IISc in the month of July.

In brief, cQED is a novel technology to tune quantum states by using electrical circuits which let photons to interact with atomic/electronic quantum states (hence QED) inside a resonator, which reflects the photons to bounce back-and-forth. Prior to the cQED, Haroche invented a technique, which is known as the cavity quantum electrodynamics (cavity-QED). In the cavity-QED a Rydberg atom (hydrogen like atom with large principal quantum number) is placed inside a cavity. The atom goes to a lower quantum state by emitting a photon. A microwave photon beam is also send inside the cavity through a small hole. The photons get reflected by the oppositely faced mirrors inside the cavity and during their back-and-forth motion they interact with the two states (higher and lower energy) of the atom. Thus the states inside the cavity remain as a superposition of two states or in a the Schroedinger cat state. Such a state forms the a qubit, which is the building block of a quantum computer.
[Interested readers can look at the 1989 Physics Today article by Serge Haroche and Daniel Kleppner and for a technical detail, the 2001 Review of Modern Physics issue by J. M. Raimond, M. Brune, and S. Haroche.]

Now for the other winner’s contribution, since I was not familiar with his name beforehand, I’ll speak a little. The video below shows David Wineland’s description of a quantum clock.

An atomic clock works on the principle of Rabi oscillation (physicist reader can take a look at the chapter 5 of J. J. Sakurai’s Modern Quantum Mechanics book), which is due to the oscillatory nature of the atomic states: an atom goes to a lower energy state by emitting light and again it comes back to the original higher energy state by absorbing the photon of the same energy (this happens in the cavity-QED as well). Instead of atoms, Wineland trapped Hg+ and Al+ by using electric field and let them interact with a visible wavelength laser with a narrow linewidth. In this way they achieved the optical clock, which has 100 times more accurate precision compared to the standard Caesium atomic clock (works in a microwave range).

Now people are saying that the Nobel prize has gone to the hands of the trappers: one has trapped photons, the other has trapped ions.

Useful references:
Article from the
An article by Wineland group


2012 Physics Nobel Prize: Predictions

Guess the nail-biting period has already started. Just two days we need to wait to know the winner(s) of the physics Nobel prize this year? However, predictions have already started since last month. I shall mention
some of the claimed predictions in this post and we’ll match them with the final result to be announced on Tuesday.

Fine, let’s mention some names in claims.

Popular prediction:

1 Peter Higgs: for the theory of Higgs boson dicosvered in the Large Hadron Collider experiments.

[I guess this is in the most popular demand (we can take an online poll and check it). After the 4th July announcement, many media took dramatic roles reporting the discovery of the ‘God particle’ and it’s almost set in many people’s mind that the theory has been tested and now the moment has come to award Peter Higgs, who is 83 years old now. But as the CERN’s results yet to be scrutinized and also I believe that debates are still open, he may not be awarded immediately. In addition to this, there’s a Higgs boson headache in deciding nobel prize winners for predicting the Higgs boson since there are four other candidates apart from Peter Higgs (Englert, Guralnik, Hagen, and Kibble) and the Nobel prize committee’s rule allows maximum three winners.]

Thomson Reuter’s yearly prediction:

2 Stephen Harris and Lene Hau: for the experimental demonstration of electromagnetically induced transparency (Harris) and of ‘slow light’ (Harris and Hau).

3 Leigh T. Canham: for the discovery of photoluminescence in porous silicon.

4 Charles Bennett, Gilles Brassard, and William Wootters: for their pioneering description of a protocol for quantum teleportation, which has since been experimentally verified.

condensedconcept (blog)’s prediction:

5 Alan Aspect, John Clauser, and Anton Zeilinger: for the experiments for testing Bell inequalities and elucidating the role of entanglement in quantum physics.

6 Duncan Haldane and David Thouless: for showing the important role of topology in low-dimensional condensed matters.

So let’s wait and watch. Hope readers will predict a few more names.

popsci article (for the photo)