Simons Collaboration on It From Qubit Second Annual Meeting

  • Organized by
  • Patrick Hayden, Ph.D.Stanford University
  • Matthew Headrick, Ph.D.Brandeis University
Date & Time

Thu.: 8 AM - 5 PM
Fri.: 8:30 AM - 3:30 PM


Gerald D. Fischbach Auditorium
160 5th Ave
New York, NY 10010 United States

This is the second annual meeting of the Simons Collaboration on It from Qubit.

Collaboration Website »

  • Agendaplus--large

    Thursday, December 7

    8:00 AMCheck-in & breakfast
    9:00 AMPatrick Hayden | Approximate Quantum Error Correction Revisited
    10:00 AMPosters | New IFQ Fellows
    11:30 AMBrian Swingle | Tensor Networks and Early Quantum Devices
    12:30 PMLunch
    2:00 PMDaniel Harlow | Lorentzian vs. Euclidean Quantum Gravity in 1+1 Dimensions
    3:00 PMBreak
    3:30 PMJohn Preskill | Quantum Computing in the NISQ Era and Beyond
    4:30 PMDay one concludes

    Friday, December 8

    8:00 AMCheck-in & breakfast
    9:00 AMAlexei Kitaev | Efficient Decoding for the Hayden-Preskill Protocol
    10:00 AMPosters | General Session
    11:30 AMScott Aaronson | An Armory of Assumptions
    12:30 PMLunch
    1:30 PMJuan Maldacena | How to Make a Wormhole
    2:30 PMMeeting concludes
  • Abstractsplus--large

    Approximate Quantum Error Correction Revisited

    Patrick Hayden, Stanford University

    The theory of quantum error correction has been firmly established as a key feature of the AdS/CFT correspondence. Mapping observables from the quantum gravitational bulk theory to the boundary conformal field theory is mathematically a problem of decoding quantum error correcting codes. This insight has led to new formulas for the mapping in cases where it wasn’t understood how to accomplish it previously, as well as resolved conceptual puzzles like how entropy, a nonlinear function of the state, can be identified with area, an observable. Hayden will describe a new theory of approximate quantum error correction appropriate for mapping observables behind a black hole horizon to the boundary. That theory is full of new surprises from the quantum information point of view, including way to squeeze two qubits into one asymptotically.

    Tensor Networks and Early Quantum Devices

    Brian Swingle, University of Maryland

    It is interesting to ask how “it from qubit” differs from “it from bit”, for example, from the point of view of computational hardness. Swingle will present two tensor network results, one in equilibrium and one out of equilibrium, that bear on the question of classical versus quantum computational hardness in physics. He will then discuss a result with Isaac Kim showing that certain renormalization group inspired tensor networks can be efficiently contracted on a small quantum device even in the presence of noise. Finally, Swingle will discuss work with Shenglong Xu showing how quantum scrambling physics can be computed using classical tensor network methods.

    Lorentzian vs. Euclidean Quantum Gravity in 1+1 Dimensions

    Daniel Harlow, Massachusetts Institute of Technology

    Daniel Harlow will describe the canonical quantization of Jackiw-Teitelboim gravity in 1+1 dimensions, taking care to extract all physical degrees of freedom. He will then use the resulting quantum gravity theory to re-interpret some existing Euclidean results in a novel way. There will be nary a Schwarzian in sight.

    Quantum Computing in the NISQ Era and Beyond

    John Preskill, California Institute of Technology

    Noisy Intermediate-Scale Quantum (NISQ) technology will be available in the near future. Quantum computers with 50-100 qubits may be able to perform tasks which surpass the capabilities of today’s classical digital computers, but noise in quantum gates will limit the size of quantum circuits that can be executed reliably. NISQ devices will be useful tools for exploring many-body quantum physics, and may have other useful applications, but the 100-qubit quantum computer will not change the world right away — we should regard it as a significant step toward the more powerful quantum technologies of the future. Quantum technologists should continue to strive for more accurate quantum gates and, eventually, fully fault-tolerant quantum computing.

    Efficient Decoding for the Hayden-Preskill Protocol

    Alexei Kitaev, California Institute of Technology

    We present two procedures for reconstructing a quantum state from the Hawking radiation in the Hayden-Preskill thought experiment. We work in an idealized setting and represent the black hole and its entangled partner by n EPR pairs. The first procedure teleports the state thrown into the black hole to an outside observer by post-selecting on the condition that a sufficient number of EPR pairs remain undisturbed. The probability of this favorable event scales as 1/dA², where dA is the Hilbert space dimension for the input state. The second procedure is deterministic and combines the previous idea with Grover’s search. The decoding complexity is O(dA C) where C is the size of the quantum circuit implementing the unitary evolution operator U of the black hole. (Based on joint work with Beni Yoshida.)

    An Armory of Assumptions

    Scott Aaronson, University of Texas, Austin

    Scott Aaronson will provide an overview of assumptions about computational hardness and what kinds of assumptions are necessary and sufficient to derive various conclusions of interest for quantum gravity.

    Aaronson will focus on the relationships among the following:

    1. “Traditional” hardness assumptions (like PSPACE not in PP/poly, or the existence of one-way functions)
    2. Assumptions about the hardness of preparing certain states (like the end result of applying a CFT Hamiltonian for exponential time)
    3. Assumptions about the hardness of applying certain unitary transformations (like that needed to decode the Hawking radiation in the firewall problem)

    Aaronson will also discuss the “Unitary Synthesis Problem,” a problem posed by Greg Kuperberg and Aaronson a decade ago that asks whether there’s any hope to justify assumptions of type (3) without needing to justify (1) or (2). Aaronson will also discuss connections to other topics, including the security of quantum money schemes. The goal of this talk is to help It from Qubit participants who might need to deploy complexity assumptions in their own work.

    How to Make a Wormhole

    Juan Maldacena, Institute for Advanced Study

    Juan Maldacena will review aspects of wormholes, thermofield double states and traversable wormholes in nearly AdS₂ spacetimes. He will then discuss a way to produce a state close to the thermofield double state in the SYK model.

  • Travelplus--large

    Air and Train

    1. Group A
      The foundation will arrange and pay for all air and train travel to the conference for those in Group A. Please provide your travel specifications by clicking the registration link above. If you are unsure of your group, please refer to your invitation sent via email.
    2. Group B
      Individuals in Group B will not receive travel or hotel support. Please register at the link above so we can capture your dietary requirements. If you are unsure of your group, please refer to your invitation sent via email.

    Personal Car

    1. For participants in Group A driving to Manhattan, The Roger Hotel offers valet parking. Please note there are no in-and-out privileges when using the hotel’s garage, therefore it is encouraged that participants walk or take public transportation to the Simons Foundation.
  • Hotelplus--large

    Participants in Group A who require accommodations are hosted by the foundation for a maximum of three nights at The Roger hotel. Any additional nights are at the attendee’s own expense.

    The Roger New York
    131 Madison Avenue
    New York, NY 10016
    (between 30th and 31st Streets)

    To arrange accommodations, please register at the link above.

    For driving directions to The Roger, please click here.

  • Contactsplus--large

    Travel Assistance
    Elise Volpe, Protravel International

    Registration, Hotel and General Meeting Assistance
    Meghan Fazzi
    Senior Executive Assistant, Simons Foundation
    (212) 524-6080

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