What is Delayed choice: Definition and 115 Discussions
Wheeler's delayed-choice experiment is actually several thought experiments in quantum physics, proposed by John Archibald Wheeler, with the most prominent among them appearing in 1978 and 1984. These experiments are attempts to decide whether light somehow "senses" the experimental apparatus in the double-slit experiment it will travel through and adjusts its behavior to fit by assuming the appropriate determinate state for it, or whether light remains in an indeterminate state, neither wave nor particle until measured.The common intention of these several types of experiments is to first do something that, according to some hidden-variable models, would make each photon "decide" whether it was going to behave as a particle or behave as a wave, and then, before the photon had time to reach the detection device, create another change in the system that would make it seem that the photon had "chosen" to behave in the opposite way. Some interpreters of these experiments contend that a photon either is a wave or is a particle, and that it cannot be both at the same time. Wheeler's intent was to investigate the time-related conditions under which a photon makes this transition between alleged states of being. His work has been productive of many revealing experiments. He may not have anticipated the possibility that other researchers would tend toward the conclusion that a photon retains both its "wave nature" and "particle nature" until the time it ends its life, e.g., by being absorbed by an electron, which acquires its energy and therefore rises to a higher-energy orbital in its atom.
This line of experimentation proved very difficult to carry out when it was first conceived. Nevertheless, it has proven very valuable over the years since it has led researchers to provide "increasingly sophisticated demonstrations of the wave–particle duality of single quanta". As one experimenter explains, "Wave and particle behavior can coexist simultaneously."
The paper described at http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser rather intrigues me.
While the results appear counter intuitive to us, the properties being tested are those of light, and since light travels at speed c, is it not the case that for light time stands still...
Could someone explain to me how the delayed choice experiment is described within the framework of the Copenhagen interpretation? (Double slit experiment with two slits open but a late decission to measure the path of the particle). I do not understand how the deterministic evolution of the...
Hello !
here is a link towards an article describing an experiment that is a realisation of Wheeler's delayed choice gedanken experiment :
http://arxiv.org/abs/quant-ph/0610241
the conclusion is quite interesting :
"Our realization of Wheeler’s delayed choice
GedankenExperiment...
I had thought up this situation where faster than light data transfer could occur, which turn out to have been thought of before. It is something called the Delayed Choice Quantum Erasure.
http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser
"...Even more surprising was that, if you...
Question: What would happen if this was delayed even further? We are talking nanoseconds here, but what if the particle was slowed or sent far away, before being reflected back? What I'm getting at is... What if the delay wasn't nanoseconds, but seconds? What if it was minutes? What if it was...
Delayed Erasure Demystified
Delayed choice quantum erasure experiments claim to produce a 2-slit interference pattern in a beam by 'erasing' the which-path information contained in an entangled beam. There's an implication that the erasure happens after the interference is measured, and that...
I have a question about the delayed choice quantum eraser with the double split experiment. Forgive me if this is a silly question.I have seen the following:
TEST 1
1. shoot the particles & measure the result
2. erase the result
3. check the wall (whatever you shot the particle at)
= wall...
http://www.joot.com/dave/writings/articles/entanglement/spookiness.shtml
http://www.joot.com/dave/writings/articles/entanglement/quantum-eraser.png
1. a laser fires photons into a Beta Barium Borate (BBO) crystal;
2. the crystal entangles some of the photons; and then
3. entangled...
String theory is touted as bridging the gap between general relativity and quantum mechanics, so I'm presuming it can explain everything in QM.
How does string theory explain the results of the two slit experiment and the delayed-choice experiment?
(pop science reader's answer, if...
In double-slit experiment one can observe either an interference pattern or which-path information, but never both.
Spontaneous parametric down conversion (SPDC) is used in the recent experiments to create entangled pairs of photons. One of them is used to observe the interference pattern...
I am a High School Senior in Advanced Physics Topics class. We have recently deiscussed the basic double slit experiments and ways of quntum erasing and delaying choices, and how those situation affect the outcome of the screen whether it will show an interference pattern or not.
We then...
My brain is in great pain from reading Greene's 'Fabric o/t Cosmos'. I'm currently on p.197 (Chapter 7: Time and the Quantum - Shaping the Past).
He's got the delayed choice setup rigged so that photons with 'which-path' info and no 'which-path' info are hitting the same screen. He says that...
Some time ago I read some stuff about delayed choice and quantum eraser experiments, but rather than reading the articles thorouhgly, I just glanced at them quickly, picked up a few ideas, and then tried to design a gedanken experiment of my own. Now I seem to have run into a bit of a problem...
I have been contemplating this experiment for quite some time now, and I have some questions. http://xxx.lanl.gov/PS_cache/quant-ph/pdf/9903/9903047.pdf is a preliminary copy of the paper describing the experiment, for reference.
The first and most obvious question would be whether it is...