It seems from @EmilioPisanty's comments on this question that the AC/optical Kerr effect is impractical for use in optical quantum computers, which leads me to ask: would the DC Kerr effect work?

The major difference between the optical/AC Kerr effect and the electro-optic/DC Kerr effect is that for the DC version to work, one must manually apply the electric field to the medium, whereas for the AC version, the light going through produces the effect itself.

In summary, is it possible to use a medium that exhibits the DC Kerr effect in place of a medium that exhibits the AC Kerr effect in an optical quantum computer?

  • 1
    $\begingroup$ In a word, no. The point of using the AC Kerr effect was to get two optical photons, which are your qubits, to interact with each other (and thus realize some two-qubit gate). Applying a DC field to manipulate a single photon, while perhaps useful for other purposes, does not do this. $\endgroup$ – Rococo Jul 15 '17 at 0:26

To formalize Rococo's comment as an answer: not really, no.

The electro-optic effect can be enormously useful in manipulating the propagation of light in the lab, through devices generally known as electro-optic modulators and their relatives, going all the way from precision spectroscopy down to manipulating the propagation of photons on a chip (example, though as I understand it photonic chips are easier to build around the thermo-optic effect).

However, that is based on external manipulation acting on the system, where the modulations come in through classical fields (either AC or DC) that (i) have very many photons, and (ii) are in completely classical states of the field. For this to be useful for quantum computation, you'd need the modulation to be triggered by one of the single photons in your computation, in a coherent, nondestructive way.

And, as explained in the previous answer, no, that's not currently possible without extensive, dedicated work on very special conditions.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.