December 2021

Date: December 2

Time: 17:30 IST (UTC + 5:30)

Speaker: Johanna Erdmenger (Univ of Wurzburg)

Title: Relating quantum information aspects of quantum mechanics and gravity

Abstract: I will present two recent works of our Wuerzburg group on this subject. First, I will present a relation between entanglement in simple quantum mechanical qubit systems and in wormhole physics as considered in the context of the AdS/CFT correspondence. In both cases, states with the same entanglement structure, indistinguishable by any local measurement, nevertheless are characterized by a different Berry phase. This feature is experimentally accessible in coupled qubit systems. I will also give a group-theory argument highlighting the different factorisation properties of the two-qubit system and the wormhole. The second project is devoted to extending the Nielsen geometric approach operator complexity to the SU(N) group and considering the large N limit. This is motivated by the aim of constructing a gravity dual for computational complexity. We implement the Euler-Arnold approach to identify incompressible inviscid hydrodynamics on the two-torus as a novel effective theory for the evaluation of operator complexity for large qudits. I will discuss the ergodicity properties of our result. Based on 2109.01152 and 2109.06190

This seminar is a part of the activities of Center for Quantum Information Theory of Spacetime and Matter of IIT Madras

VIDEO: Click here

Date: December 6

Time: 18:30 IST (UTC + 5:30)

Speaker: Anatoly Dymarsky (Univ of Kentucky)

Title: Quantum codes, conformal field theories, and holography

Abstract: I will review recently introduced connection between quantum error correcting codes and a family of Narain CFTs, which we call "code theories." Some of these code theories maximize spectral gap for the given value of central charge, making connection with the conformal bootstrap program. From the holographic point of view, code CFTs form an ensemble which provides a simplified model for the recently introduced duality between ensembles of boundary theories and quantum gravity in the bulk. In the talk I will first describe the mapping between quantum codes and Narain theories, and then discuss how codes can be helpful for bootstrap, in particular the task of finding optimal CFTs which maximize the spectral gap. In the second part of the talk I will discuss the ensemble of code theories and several lessons they teach us about the ensemble of all Narain theories and its holographic description.

This seminar is a part of the activities of Center for Quantum Information Theory of Spacetime and Matter of IIT Madras

VIDEO: Click here