 |
A New Era of Experimentation with Quantum Physics
|
|
|
|
Unit 12
A New Era of Experimentation with Quantum Physics
The Nobel Prize in Physics 2012 — Popular Release
October 9, 2012
The Royal Swedish academy of Sciences decided to award the Nobel Prize in Physics for 2012 " for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems". The Nobel Prize is awarded to Serge Haroche Collè ge de France and Ecole Normale Supé rieure, Paris, France, and David J. Wineland National Institute of Standards and Technology (NIST) and University of Colorado Boulder, CO, USA.
Read the text and explain what Serge Haroche’s and David J. Wineland’s scientific and technological breakthrough consists in.
Particle control in a quantum world
Serge Haroche and David J. Wineland have independently invented and developed methods for measuring and manipulating individual particles while preserving their quantum-mechanical nature, in ways that were previously thought unattainable.
The Nobel Laureates have opened the door to a new era of experimentation with quantum physics by demonstrating the direct observation of individual quantum particles without destroying them. For single particles of light or matter the laws of classical physics cease to apply and quantum physics takes over. But single particles are not easily isolated from their surrounding environment and they lose their mysterious quantum properties as soon as they interact with the outside world. Thus many seemingly bizarre phenomena predicted by quantum physics could not be directly observed, and researchers could only carry out thought experiments that might in principle manifest these bizarre phenomena.
Through their ingenious laboratory methods Haroche and Wineland together with their research groups have managed to measure and control very fragile quantum states, which were previously thought inaccessible for direct observation. The new methods allow them to examine, control and count the particles.
Their methods have many things in common. David Wineland traps electrically charged atoms, or ions, controlling and measuring them with light, or photons.
Serge Haroche takes the opposite approach: he controls and measures trapped photons, or particles of light, by sending atoms through a trap.
Both Laureates work in the field of quantum optics studying the fundamental interaction between light and matter, a field which has seen considerable progress since the mid-1980s. Their ground-breaking methods have enabled this field of research to take the very first steps towards building a new type of superfast computer based on quantum physics. Perhaps the quantum computer will change our everyday lives in this century in the same radical way as the classical computer did in the last century. The research has also led to the construction of extremely precise clocks that could become the future basis for a new standard of time, with more than hundred-fold greater precision than present-day caesium clocks.
|
|
|
(http: //www. nobelprize. org/nobel_prizes/physics/laureates/2012
/press. html )
David Wineland — Interview
Read David Wineland’s Nobel interview and answer the questions
a) What is David Wineland’s main interest?
b) What method does Wineland use to trap single atoms to observe the superposition of quantum states?
c) What chemical element are the clocks Wineland designs based on?
d) How close is modern physics to quantum computing?
" It's a long way before we have a useful quantum computer, but I think most of us... feel that it will eventually happen"
[Adam Smith] – Oh hello, I'm sorry to call so very early, may I speak to Professor David Wineland please?
[David Wineland] – Yes, this is he.
[AS] – Oh good morning, my name is Adam Smith, from the Nobel Prize website in Stockholm. We have a tradition of recording extremely short interviews with new Laureates. Would you be able to speak for just a very few minutes?
[DW] [Laughs] – Sure. Okay.
[AS] – Thank you very much indeed. First of all, of course, our sincere congratulations on the award of the Nobel Prize.
[DW] – Oh, thank you.
[AS] – I know it's extremely early in the morning, in fact the middle of the night there. What were you doing when the call from Stockholm came?
[DW] – Well, I was sleeping, and my wife got the call and woke me up.
[AS] [Laughs] – Do you recall your initial reaction?
[DW] – Well, I mean a wonderful surprise, of course. Yes, just amazing, sure.
[AS] – I imagine it's thrown the house into some kind of disruption there.
[DW] – Well, we probably won't go back to sleep for a while [Laughs]. Yeah.
[AS] – I guess there's the normal business of life to run alongside handling the press that are about to descend on you.
[DW] – That's right, yeah.
[AS] – Your main interest, I gather, is developing far more accurate clocks and that's what you've been devoted to in your career.
[DW] – That's been the main theme. Yes, but there's been many spin-offs from that, including the work on single atoms.
[AS] – And the trapping of single atoms, this allows you to observe the superposition of quantum states?
[DW] – That's right.
[AS] – This is basically observing, if you like, the frontier between the classical world where the states don't superimpose and quantum states where you can have multiple states at the same time.
[DW] – Well, you might say that. That's right, yes.
[AS] – How do you trap the atoms?
[DW] – Well, in our case the atoms are ions, charged atoms. So we use electric fields to hold them in one place.
[AS] – And then you use laser beams to manipulate them, is that correct?
[DW] – That's right.
[AS] – Tell me more, please, about why need more accurate clocks.
[DW] – Well, I think historically it's always been true that when we've made better clocks there's always been an application. The main use throughout history for the last many centuries is that clocks are used in navigation and the better clocks we have the better navigation we can do. So that theme has carried through for many centuries. As we make better clocks that's still been the primary application. These days also the timing, the precise timing, you know, by good clocks is also used in communication. But historically the main use has been and continues to be in navigation.
|
|
|
[AS] – And how accurate are our most accurate clocks now? You have this mercury ion clock.
[DW] – Currently the most accurate one is also in our lab. It's based on aluminium. And accuracy meaning, you know, how well we can control the environmental effects and so on, is at about one part in 10 to the 17.
[AS] [Laughs] – And how long can you keep it running for? Is it indefinite?
[DW] – Well, so far these are laboratory devices. So they do not work continuously, but they can work many hours and days to produce these results.
[AS] – So the other application that is often talked about is quantum computing.
[DW] – Right.
[AS] – And does your work take us a step closer to quantum computing?
[DW] – Well, I think you might say that. But in the same breath, you have to say that it's a long way before we have a useful quantum computer. But I think most of us feel that even though that is a long, you know, long way off before we can realise such a computer, many of us feel it will eventually happen. It's primarily a matter of controlling these systems better and better. Both Serge Haroche and I work on atoms. There's many other platforms and condensed matter where this might happen. But wherever it happens I think we believe that in the long run we should be able to [inaudible] well enough to realise such a device.
[AS] – May I ask you, you work at the National Institute of Standards and Technology and it seems to be a hotbed for the production of new inventions and, indeed, Nobel Laureates. What is it that's so special about this place?
[DW] – I think that, one of the things, you know, certainly is the people, my management. People above me have been very supportive of these things. You know, it couldn't happen without that. I think supportive management, and it helps being around very good people. That's made the difference.
[AS] – Must be a very exciting place to be. And, indeed, it must be extraordinarily exciting looking at this new frontier, being the first to observe this new world of quantum states, which haven't been previously observable.
[DW] – Well, I wouldn't say... I wouldn't put myself in the first, you know, maybe we're among the first. But there's many good people working on these things though. It's certainly a big enterprise by now and many people are working on this in this area.
[AS] – Sure, but there must be a constant thrill of excitement, of feeling you're on uncharted territory.
[DW] – Well, yeah, that's been really true in science, to be near the leading edge, I suppose. Yeah, it's always been great, really exciting to be in this field. [AS] – Thank you so much for talking to us. Again, apologies for calling in the very middle of the night... [both laugh]... when you come to Stockholm in December we have the chance to interview you at a greater length, which we very much look forward to. But for now, I wish you the very best of luck with what will surely be an exciting day.
[DW] – Well, thanks very much. All right, thank you.
[AS] – Thank you. Nice to speak to you. Bye bye.
[DW] – Bye bye.
(http: //www. nobelprize. org/nobel_prizes/physics/laureates/2012/wineland-interview. html)
|
|
|
