Oct 2018 Kickoff Meeting

Location

Le Conte 375, UC Berkeley, October 4-5, 2018

Summary

The QuantISED consortium "The Geometry and Flow of Quantum Information: From Quantum Technology to Quantum Gravity” held its first meeting on October 4 and 5 in Berkeley. It was attended by 11 of the 12 PIs (with Monroe giving a talk via Skype), and by about 40 students and postdocs.

The chief goal of the meeting was to identify and pursue scientific advances that our consortium is uniquely positioned for. In light of the short grant period, we gave particular attention to “initial deliverables” that can be accomplished on a one to two year timescale. This will likely include not only theoretical advances, but also concrete, fully formulated experimental proposals, and perhaps even some experimental results. A brief summary of the subjects that were discussed are as follows.

Theory:

• Ehud Altman discussed potential applications of tensor networks to understanding scrambling and phase transitions in entanglement entropy.
• Ning Bao discussed inequalities that are true for holographic entanglement entropy, and suggested reasons why these inequalities should extend to low-energy physics systems as well.
• Raphael Bousso discussed bounds derived via quantum gravity theories in which the gravity dependence decouples in certain limits, and proposed that such cases could be interesting testbeds for experimental study.
• Charles Cao, speaking on behalf of Brian Swingle, talked about ways of finding emergent quantum geometry, motivated by AdS/CFT, in quantum many-body systems.
• Patrick Hayden discussed a way of measuring Renyi entropies using a quantum virtual cooling process, in a way that might make high energy and quantum information motivated conjectures to be more easily testable using qubit systems.
• Yasunori Nomura discussed various ways in which tensor network models of holography can be adapted to study dynamical spacetimes.
• Xiaoliang Qi discussed whether there was a way of studying computational complexity, perhaps in the context of holography, from an entropic perspective.
• Norm Yao discussed ways in which scrambling could manifest in different qubit systems, and ways of quantifying it in both a theoretical and experimental context.
• Michael Zaletel discussed ways of evaluating the entanglement of purification, both holographic and in spin chains, and discussed how such quantities can be studied in experiment.

Exp 1 (Monroe): Monroe’s ion-based quantum computing platform was presented to the collaboration. In particular, its very high qubit rest fidelity, relatively high (~50) qubit count, and potential for single-site control makes it an optimal testbed for precise quantum information-theoretic protocols which require such precise control.

Exp 2 (Schleier-Smith): The neutral atom quantum simulation platform of the Schleier-Smith group was presented to the collaboration. Its access to many thousands of qubits with local imaging and addressing, albeit without single-particle control, is well suited to be adapted to modeling black hole physics as related to quantum information, and applying concepts of quantum metrology to track the dynamics of multipartite entanglement, where the specific single-qubit control is less important than the sheer number of qubits available.

Exp 3 (Siddiqi): The superconducting qutrit setup of the Siddiqi group was also presented to the collaboration. The specialization to qutrits instead of qubits, in addition to single-site addressability, allows for interesting specialized studies on this platform, from scrambling experiments to studying dynamics of certain holographic error correcting codes.

Schedule

10/4

9:00 AM: Raphael Intro

9:05 AM: Chris Monroe

9:50 AM: Irfan Siddiqi

10:35 AM: Coffee Break

10:50 AM: Monika Schleier-Smith

11:35 AM: Discussion

12:30 PM: Lunch

1:30 PM: Norm Yao

2:15 PM: Ning Bao

3:00 PM: Coffee Break

3:15 PM: Raphael Bousso

4:00 PM: Discussion

6:15 PM: Depart for Dinner for PI's at Great China (Reservation time 6:45)

10/5

9:00 AM: Mike Zalatel

9:45 AM: Xiaoliang Qi

10:30 AM: Coffee Break

10:45 AM: Ehud Altman

11:30 AM: Discussion

12:30 PM: Lunch

1:30 PM: Yasunori Nomura

2:15 PM: Patrick Hayden

3:00 PM: Coffee Break

3:15 PM: Charles Cao

4:00 PM: Discussion

5:30 PM: Conclude