July 2021 - ITP-quantumseminare - lists.phys.ethz.ch

no QIT Seminar this week
by Joe Renes 26 Jul '21

26 Jul '21

Hi all, There's no QIT Seminar this week. Best, Joe

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This week's QIT Seminar --> Thursday at 11am
by Joe Renes 19 Jul '21

19 Jul '21

Hi all, Johannes Bausch from Cambridge will give this week's QIT Seminar, which will take place Thursday morning at 11am. He'll tell us about "Complexity, Quantum Information and Quantum Algorithms"; see below for the abstract. Usual zoom channel: https://ethz.zoom.us/j/362994444 Best, Joe %%%%%%%%%%%%% Abstract: Loosely speaking, complexity theory is the study of how hard or easy it is to answer certain computational problems. I will be presenting three areas of quantum theory in this context. First I will focus on the study of error correction codes in the communication context, utilizing novel computational techniques such as neural network quantum states and graph states to push known noise thresholds beyond the state-of-the-art. The next topic will be on many-body systems, utilizing spectral techniques to prove that various macroscopic properties such as ground state energies, spectral gaps, or phase diagrams can be hard to compute, or even undecidable. Finally, I will focus on the algorithmic side of quantum computation, and present our recent work on improving quantum simulation of the Fermi Hubbard model, and recurrent (quantum) neural networks.

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Tomorrow's QIT Seminar
by Joe Renes 12 Jul '21

12 Jul '21

Hi all, Tomorrow Jinzhao will tell us about "The refined quantum extremal surface prescription from the asymptotic equipartition property". See below for the abstract. Usual time and place: 2pm https://ethz.zoom.us/j/362994444. Best, Joe %%%%%%%% The quantum extremal surface prescription, born out of the Ryu Takayanagi formula in AdS/CFT, is a general rule of computing entanglement entropy in gravity. Its usefulness is highlighted in the recent black hole Page curve calculation. In this talk I will introduce the recent refinement of the QES prescription, showing the significance of the smooth conditional min/max-entropies. Inspired by the asymptotic equipartition property, I will sketch a path integral derivation of it in the context of holography with a novel replica trick. In the end, I will show that the derivation implies the correction also applies beyond AdS/CFT and in particular to the Page curve.

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Tomorrow's QIT Seminar
by Joe Renes 05 Jul '21

05 Jul '21

Hi all, Tomorrow Michał Bączyk will tell us about his master's thesis on "Black Hole Holographic Models in the framework of Gaussian Quantum Information", supervised partly by Mischa. See below for the abstract. We'll start at 2pm on zoom: https://ethz.zoom.us/j/362994444. Best, Joe %%%%%%%%% Title: Black Hole Holographic Models in the framework of Gaussian Quantum Information Abstract: In this work, we make the first step towards introducing the operational quantum information notions into the framework of Conformal Field Theories and AdS/CFT correspondence. We provide an original toolkit for investigating the action of Bosonic Gaussian channels on the QFTs incorporated into the language of Gaussian Quantum Information. Specifically, we study the quench protocol dynamics for the case of vacuum state of 1D harmonic chain system and the TFD state. These are Gaussian states that have meaningful dual descriptions in the language of AdS/CFT correspondence. To evaluate the character of the free and interrupted by channels evolution we calculate numerically for the systems of interest quantum entropies and fidelities all using recent advances in the Gaussian Quantum Information.

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