Junior and senior physics majors attend our biweekly colloquium series, held on Tuesday afternoons at 4:30 pm in Shanahan B460. The talks are open to all students and to the public, and are frequently attended by scientists from the other Claremont Colleges, Cal Poly Pomona, and others. The series features speakers from a broad range of institutions and fields of physics.

HMC Physics Colloquium shot
March 31, 2015 Emma Wollman, Caltech
Evidence of quantum squeezing of motion in a mechanical resonator

Quantum mechanics places limits on the minimum energy of a harmonic oscillator via the ever-present “zero-point” fluctuations of the quantum ground state. Through squeezing, however, it is possible to decrease the noise of a single motional quadrature below the zero-point level as long as noise is added to the orthogonal quadrature. While squeezing below the quantum noise level was achieved …

March 10, 2015 Jason Rhodes (’94), Jet Propulsion Laboratory
Exploring the Dark Sector with Euclid and WFIRST

The past decade has seen the emergence of the so-called “concordance model” of cosmology. In this model, the Universe started about 13.7 billion years ago in a Big Bang and is now dominated by dark matter and dark energy. Together this poorly understood “dark sector” makes up about 95% of the Universe, but the nature of these phenomena remains elusive. …

March 3, 2015 Jason Gallicchio, University of Chicago
A Long Winter: Cosmic Microwave Background Polarization with the South Pole Telescope

The South Pole Telescope is the largest Cosmic Microwave Background telescope in the world. Its high-resolution maps were the first to show evidence of so-called B-mode polarization due to gravitational lensing by intervening matter. Wider maps are now shedding light on the larger-sized B-modes generated by gravity waves created a right after the big bang. I will discuss the technology …

Feb. 24, 2015 Luis A. Orozco, University of Maryland
Optical Nanofibers

Nanofibers are a versatile platform for applied and fundamental studies. I will present our work starting with the production and characterization of the fibers. Then I will show that Rayleigh scattering from modes on the nanofiber gives information about the diameter with sub-micron resolution. We are using nanofibers for quantum optics and quantum information studies. We use the evanescent fields …

Feb. 10, 2015 Colin V. Parker (’06), James Franck Institute and Department of Physics, The University of Chicago
Dispersion Engineering with Cold Atoms: Ferromagnetism, Rotons, and Beyond

For classical or quantum Hamiltonians, one typically writes the kinetic energy, or dispersion, as a simple parabola for small momentum. However, particles traveling in certain periodic potentials (i.e. lattices) may have a dispersion that is minimized at multiple values of momentum or that depends upon the fourth power of momentum, preventing such a simple description. My collaborators and I have …

Feb. 3, 2015 Andrew Grier (’04), Columbia University
Extreme Quantum Mechanics: Quantum simulation of many-body systems using ultracold atomic gases

What happens when the strength of interactions between atoms is turned up to infinity? What about when one mixes two types of superfluids? In this talk, we will explore how ultracold atomic gases are used to create and probe these types of systems. I will discuss our recent success producing and studying extreme quantum states in ultracold lithium gases including …

Jan. 27, 2015 Ben Olsen, Rice University
Ultracold Atomic Superfluids in 3D, 1D, and in Between

Atomic gases cooled to nanokelvin temperatures can be used to study the physics governing exotic many-body quantum systems, some of which are too complicated for computer simulation. Several many-body systems, including superconductors and neutron stars, exhibit frictionless flow, or superfluidity. We experimentally probe the fermion pairing that leads to superfluidity using laser-trapped clouds of ultracold lithium atoms in two spin …

Nov. 18, 2014 Clifford Johnson, University of Southern California
Black Holes and Holographic Heat Engines

New work has shown how to complete the correspondence between the physics of black holes and the laws of thermodynamics by incorporating volume and pressure into the formalism. This results in a change in the interpretation of the black hole's mass, and may give a new handle on understanding aspects of theories of gravity with non-vanishing cosmological constant. This subject …

Nov. 4, 2014 Karen E. Daniels, North Carolina State University
Playing with Sand: Complex Behaviors from a Simple Material

Granular materials are integral to many parts of our daily lives, from the coffee beans that fuel our mornings to the coal that fuels our power plants. At first glance, these materials might appear simple: macroscopic dry, cohesionless particles which interact only by contact forces. However, they represent a complicated phase of matter neither wholly solid nor wholly liquid: a …

Oct. 7, 2014 Jeffrey Filippini, Caltech
Listening for the Echoes of Inflation with BICEP2 and Beyond

Our modern account of cosmic history begins with a period of extraordinarily rapid expansion known as inflation. This epoch established the large-scale geometry and uniformity of our universe, as well as sowing the seeds of later galaxy formation. Inflation should further have imprinted a spectrum of primordial gravitational waves onto the universe at cosmological scales. These gravitational waves should have …

Sept. 30, 2014 Vatche Sahakian, Harvey Mudd College
Whither Gravitational Waves
Sept. 16, 2014 HMC students, Harvey Mudd College
Off-campus summer research in physics

Kaew Tinyanont, Jim Wu, Miranda Thompson, Alex Kendrick, Allison Mis, Luke St Marie, and Celeste Melamed speak about their research experiences.

April 29, 2014 Bruce Schumm, University of California at Santa Cruz
Deep Down Beauty: Particle Physics, Mathematics, and the World Around Us

Almost everyone has heard of the Standard Model of Particle Physics, and, while stifling a yawn, can regurgitate its particle content: six quarks, a handful of force particles like the photon and gluon, and of course now the Higgs boson. But what many fewer enjoy is an appreciation for the deep underlying mathematical structure that, once grasped, reduces the principles …

April 22, 2014 Omer Blaes, University of California at Santa Barbara
Dwarf to Super Novae: How Dead Stars Occasionally Light Up and Tell Us About the Universe

Billions of years in the future, our Sun will eventually run out of all of its fuel and will turn into an extraordinarily dense, Earth-sized star known as a white dwarf. Most white dwarfs, including our future Sun, slowly fade into oblivion, but if they can steal matter from another nearby star, they can rejuvenate themselves. Many such “new stars”, …

April 8, 2014 Alan Guth and John Kovac, via edited video of a colloquium at Harvard from 25 March 2014, Harvey Mudd College
Peeking Under the Cosmic Veil

“For decades circumstantial evidence from observational cosmology has suggested that our universe may have started with a bang — an initial violent explosion and expansion of space known as inflation. As the universe expanded, it cooled down from an initial super hot and opaque primordial soup of mass and energy. At some point around 300,000 years after the initial bang, …