Past Events

Butcher Auditorium, A115, JSCBB 3415 Colorado Ave, Boulder, CO 80303

I’ll discuss two experimental results that utilize the collective emission of strontium atoms within a cavity, aimed at advancing atomic clock technology. In our first investigation, we employ superradiant pulses from the cavity mode as a fast and directed atomic population readout, mapping out a unique Ramsey spectroscopic lineshape and demonstrating the potential for multiple readouts within a single experimental cycle. In our second investigation, we extend these pulses using an incoherent repumping scheme, achieving steady-state lasing for over a millisecond on the kHz transition.

Abstract: Planetary atmospheres are not static in time, and the many changes they experience can contribute to making the planet’s surface a more (or less) hospitable place. Interactions between the planet and its host star are especially important, and not only control the temperature of an atmosphere but can drive atmospheric escape and atmospheric chemistry.

Abstract: It is likely both intuitive and familiar that, as you walk further from a campfire, you feel less of its heat. And yet the same is not true for the great fireball in the sky: our sun. In fact, the Sun’s corona is millions of kelvin hotter than its photosphere, despite being much further away from the center of the star. From 2020 through 2021 a team of over a thousand undergraduate students at CU Boulder painstakingly analyzed the X-ray emissions of hundreds of individual solar flares in search of evidence to help resolve this mystery.

Join CU Wizards for November's show "There's Something in the Air!" a program that's all about the Earth's atmosphere.

Professor Brown travels the world to study the amazingly thin, invisible, ethereal stuff that blankets our amazing planet and makes life on Earth possible. Have you wondered...Why is the Sky Blue!?  Why are sunrises orange?  What is air made of exactly? Did you know the Earth wears sunglasses!?  And what's the story about the greenhouse gases that are slowly but steadily warming the Earth?

Abstrace:  Back in 1973, Sidney Coleman and Nobel Prize winner David Gross proved that only non-abelian gauge theories can have asymptotic freedom.

Abstract:

Coffee, tea and cookies will be available in G1B31 (across from G1B20) from 3:30–3:50 p.m.

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Butcher Auditorium, A115, JSCBB 3415 Colorado Ave, Boulder, CO 80303

-Postdoc Group Panel-"Insert Your Funding Agency" Proposal Panel-Learn how to navigate the many different funding opportunities for postdocs-Speakers: JILA Fellows Heather Lewandowski and Ann-Marie Madigan-X317-Snacks will be provided!

• Abstract:This talk has two parts. In the first part I’ll reflect on the current status and prospects for quantum computing. In the second part I’ll describe recent results about using classical machine learning and quantum data to predict properties of complex quantum systems. In particular, these results highlight the potential for machine learning models to predict the output of a complex quantum process much faster than the time needed to run the process itself.

Abstract: In this talk, I discuss the interactions between stellar hosts and planetary companions, including the ejection and ingestion of stellar companions. Drawing insights from stellar evolutionary models and observational survey data (photometric and spectroscopic), I present my team's latest discoveries as we seek to identify unambiguous ingestion-derived chemical tracers.

Abstract: The interstellar medium provides an enormous laboratory for the exploration of chemistry of various kinds. But it is not a laboratory that we control, and its results - while resting on processes that individually may occur very rapidly - unfold on timescales that are typically much longer than a human lifetime. Our observations of the molecular compositions of interstellar clouds and star-forming regions represent only snapshots of a process of chemical evolution that must be pieced together through various means.

Abstract: Current through a resistor exhibits temperature-dependent white noise fluctuations called Johnson-Nyquist noise. For a 2D electron system, measuring the magnitude of these fluctuations provides a direct measurement of the electron temperature, and thereby enables a novel method for inferring specific heat and thermal conductivity. Here I present three general theoretical results about Johnson noise thermometry in both the ohmic and hydrodynamic limits.