Graduate

I'll discuss old and new motivations for a string theory description of the critical behavior of the 3d Ising model. Then I'll modify the Ising model so that the string theory is under better theoretical control, and describe the effects of this modification on the phase diagram. I'll conclude with some comments about the worldsheet theory.

Based on 2003.04349, with Nabil Iqbal.

Quantum computers powered by hundreds of gate based, superconducting qubits are just over the horizon. Several groups have already announced activities on quantum processors (QP) of 50 qubits or more. The systems containing these processors will be of fundamental importance in quantum algorithm development, on our path toward quantum advantage in the noisy intermediate scale quantum (NISQ) era. Quantum advantage is the point at which quantum computers can solve a problem faster, cheaper, or more accurately than their classical counterparts, which is likely to be accomplished before fully fault tolerant machines are available. This talk will address the trade-offs in the design of hybrid quantum-classical computing systems based on gate based superconducting processors approaching 100 qubits.

EE Students and Postdocs,

We understand the last few weeks have been stressful for many of you. This has been a time of much uncertainty and great transition at a moment's notice. To show support for our EE community and answer any inquiries you may have, the Electrical Engineering Department will hold a town hall meeting this Monday, March 30th, 2020 from 10am-11am (Pacific Daylight Time).

Please RSVP forms.gle/fa6XVMkTo912dRAc7
*You can list up to 3 questions on the RSVP form. You can also ask questions during the meeting using the chat function in Zoom.

The panelists include:

• EE Department Chair: Prof. Stephen Boyd
• EE Associate Chair of Graduate Education: Prof. Brad Osgood
• EE Interim Associate Chair of Undergraduate Education: Prof. John Pauly
• Director of Finance and Operations: Mary K. McMahon (moderator)
• Director of Student and Academic Services: Meo Kittiwanich

We hope you can make it. Please stay safe and take care.

Modern large-scale statistical models require to estimate thousands to millions of parameters. Understanding the tradeoff between statistical optimality and computational tractability in such models remains an outstanding challenge. Under a random design assumption, we establish lower bounds to statistical estimation with two popular classes of tractable estimators in several popular statistical models. First, in high-dimensional linear models we show that a large gap often exists between the optimal statistical error and that achieved by least squares with a convex penalty. Examples of such estimators include the Lasso, ridge regression, and MAP estimation with log-concave priors and Gaussian noise. Second, in generalized linear models and low-rank matrix estimation problems, we introduce the class of 'general first order methods,' examples of which include gradient descent, projected gradient descent, and their accelerated versions. We derive lower bounds for general first order methods which are tight up to asymptotically negligible terms. Our results demonstrate a gap to statistical optimality for general first order methods in both sparse phase retrieval and sparse PCA.

This is joint work with Andrea Montanari and Yuchen Wu.

I will argue that 2D Jackiw-Teitelboim (JT) gravity is a good approximation for some observables related to near extremal black holes in higher dimensions, beyond the semiclassical limit. In the first part of the talk I will apply this to the calculation of the density of states of charged black holes in 4D and give a resolution of the thermodynamic "mass gap" puzzle. In the second part, I will apply this to the calculation of the partition function and IR limit of boundary correlators of near extremal rotating BTZ in 3D. An independent boundary 2D CFT bootstrap argument shows that the emergence of a JT gravity sector is universal.

The development of microscopic detection of ensembles of neutral atoms has transformed our ability to study complex many-body systems. Techniques like quantum gas microscopy and optical tweezer arrays grant a unique single-particle-resolved perspective on solid-state analogs and idealized quantum spin models, as well as novel detection capabilities for quantities like entanglement. In this talk, I will describe our progress towards developing these tools for a new atomic species, strontium. In doing so, we establish new prospects enabled by the rich internal degrees-of-freedom associated with alkaline-earth atoms. I will report on our recent results in which we apply our platform to optical atomic clocks, a new application of optical tweezer arrays which indicates a number of strengths for metrology. In particular, I will describe our strategies for reaching arrays with hundreds of tweezers with sub-Hz atom-optical coherence, 41 seconds of atomic coherence, and atomic stability on par with the state-of-the-art. I will then describe our parallel progress towards engineering entanglement on an optical clock transition, as well as new scaling strategies involving atom-by-atom assembly in optical lattice potentials.

About Women of Silicon Valley 2020

With a progressive agenda engineered to bring attendees into the next generation of tech, Women of Silicon Valley will continue to support and inspire the women working in America's global capital of innovation. Bringing you an unprecedented line up of speakers, actionable insight, networking and expert-led workshops, this dynamic event will assist you in taking positive action in your own career and in your organization.

This event is built for women, by women and will act as a vital tool in your development and progression; join us and show why women in Silicon Valley do tech better than anywhere else.

Virtual courses begin in all schools except the Graduate School of Business, School of Law and School of Medicine. These three professional schools will follow their already planned spring schedules. This delay will allow instructors time to develop course offerings that are consistent with Stanford's expectations of a high-quality learning experience. The delay also will offer students and instructors who are still finishing winter quarter exams a chance to rest and recuperate after a particularly challenging quarter.

In hopes of re-starting our seminar series, we will have our first virtual seminar via zoom on Monday, March 23 at 2pm. Before the seminar, we will begin with a virtual "town meeting" (again via zoom) from 1:30 to 2pm to just check with people on how everybody is doing during this uncertain period. Hope to see you there!

Zoom link: https://stanford.zoom.us/j/784962786

Despite being some of the first and most basic objects one encounters in the study of algebra, finite simple groups are surprisingly rich, and participate in a variety of mysterious connections to other areas in math and physics. The classification of finite simple groups is a remarkable theorem of pure mathematics which brings their mystique to bear. Indeed, much as in the more familiar classification of simple Lie groups, there are exceptional cases --- the so-called "sporadic groups" -- which are relatively poorly understood. Since group theory is the abstraction of the study of symmetry, it is natural to ask what structures exactly they act on by symmetries. Generalizing the observations of monstrous moonshine, we will argue that many of the sporadic groups naturally arise as the global symmetries of distinguished conformal field theories in two dimensions. In the process, we will be able to compute the torus partition functions of these theories by solving a kind of highly-constrained modular bootstrap problem using methods, old and new, from the theory of modular forms.