What is Quantum erasure: Definition and 14 Discussions

In quantum mechanics, the quantum eraser experiment is an interferometer experiment that demonstrates several fundamental aspects of quantum mechanics, including quantum entanglement and complementarity.
The quantum eraser experiment is a variation of Thomas Young's classic double-slit experiment. It establishes that when action is taken to determine which of 2 slits a photon has passed through, the photon cannot interfere with itself. When a stream of photons is marked in this way, then the interference fringes characteristic of the Young experiment will not be seen. The experiment also creates situations in which a photon that has been "marked" to reveal through which slit it has passed can later be "unmarked." A photon that has been "marked" cannot interfere with itself and will not produce fringe patterns, but a photon that has been "marked" and then "unmarked" will interfere with itself and produce the fringes characteristic of Young's experiment.

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  1. B

    I Quantum eraser in Bohmian Mechanics and many worlds theory

    All the literature on the quantum eraser that I've seen is grounded in the Copenhagen interpretation of quantum mechanics. It's very easy to understand the experiment in those terms. Do you know how quantum eraser experiments are interpreted by the de Broglie–Bohm theory? What is erased in this...
  2. andrewkirk

    Polarisation destroying interference pattern for double slit

    I have been trying to mathematically explain the empirical result that putting orthogonal polarisers (quarter-wave plates) behind the two slits of a double-slit setup will erase the interference pattern. The trouble is, my analysis predicts an interference pattern. I must have made a silly...
  3. andrewkirk

    Kim's delayed choice quantum eraser -- Is it really delayed?

    I have been mulling over various aspects of delayed quantum erasure and came upon the following puzzle. It is about the famous 'delayed choice quantum eraser' of Kim, Kulik, Shih and Scully. The paper says (1st para of 2nd column on p2) that the path length from the BBO crystal that generates...
  4. R

    Question about quantum erasure experiment

    I'm not a physicist, but I have a layman understanding of some aspects of Quantum Mechanics. I just watched a video explaining the experiment, where you put two differently polarized sheets behind each slit, but then erase the polarization with third polarizing sheet that's located between the...
  5. S

    Questions about Quantum erasure with causally disconnected choice

    Hello, Interested mostly-amateur here with some questions about the Quantum erasure with causally disconnected choice experiments conducted in Vienna and the Canary Islands by Ma, Zeilinger et al. 1. Does the projection event of the system photon's entangled partner occur AFTER the system...
  6. J

    Controlled delayed quantum erasure?

    In standard delayed choice quantum erasure experiment ( http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser ), the which-way information is randomly erased in one path, what chooses between classical and quantum behavior for the second path (if there is interference pattern). The...
  7. T

    Is predicting the future with Quantum Erasure possible?

    Hi I tried to post this before but it got messed up. hopefully it doesn't post twice. I'm new to this forum and signed up just to ask this question. I have just read this website and it has helped me to understand the basic problems of quantum mechanics. After thinking about the quantum erasure...
  8. X

    Questions about the delayed choice quantum erasure experiment

    Hello, the delayed choice quantum erasure experiment seems really intriguing and although many sources seem to state that the results are what has been predicted by quantum mechanics, I'm having a very hard time understanding the results conceptually. What is exactly happening that causes there...
  9. A

    (in)coherent superposition and quantum erasure

    Hi I am currently reading John Preskill's Lecture Notes on Quantum Information and Quantum Computation (see http://www.theory.caltech.edu/people/preskill/ph229/index.html near the bottom of the page). I am confused about what he writes in chapter 2.5.4: Quantum erasure. He starts with the...
  10. J

    Delayed Quantum Erasure Double Slit with Observer Choice Available

    In the paper "Double-Slit Quantum Eraser" by Walborn, Cunha, Padua, and Monken (see http://grad.physics.sunysb.edu/~amarch/Walborn.pdf and discussion of the paper at http://grad.physics.sunysb.edu/~amarch/ ), a double-slit quantum erasure experiment is performed with a delayed eraser. When the...
  11. M

    Effect for time lag in quantum erasure?

    When which way information is erased, interference reappears. Is there any theoretical and experimentally confirmed evidence that the interval between pair creation and erasure has any effect? The experiments I've read seem more concerned with evidencing the erasure and delayed erasure result...
  12. C

    Delayed Choice Quantum Erasure

    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...
  13. B

    Delayed Choice Quantum Erasure Demystified

    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...
  14. Z

    Quantum Erasure 9903047 - Issues

    The Quantum Erasure experiment by Scully et al http://arxiv.org/abs/quant-ph/9903047 appears to have generated more questions than it has settled. Please look at attached figure below, which I believe is isomorphic to their quantum erasure experiment Fig. 2. Photons A and B are entangled...