Probing strings with quantum extremal surfaces

Abstract: We drop a particle or string into vacuum AdS and ask whether the excitation is in the entanglement wedge for a region composed of a Rindler wedge together with a small interval. We compute the quantum fidelity between the state with a particle and the state without a particle, which is a direct measure of whether the particle is reconstructable from this region. We find that in a gravitational theory and for a purely chiral probe particle, the distinction of whether the excitation is in the entanglement wedge or not is sharp, corresponding precisely with when the excitation passes across the quantum extremal surface. For a theory with a non-zero string length, we find that this distinction between when the particle is inside or outside the entanglement wedge becomes fuzzy and depends on the smearing scale of the particle creation operator. We comment on an interpretation of this phenomenon in terms of string spreading. Based upon forthcoming work with Ven Chandrasekaran and Tom Faulkner.

HEP - theorymathematical physicsquantum physics

Audience: researchers in the topic

( video )

Purdue HET

Series comments: The recorded talks will be available on YouTube here: www.youtube.com/playlist?list=PLxU3vHZccQj64m9zsQR74D5WP1z1g4t1J