Harvard University Department of Physics

How Termite Mounds Get Their Shape

New research is shedding light on the principles of termite mound size and shape with a model coupling insect behavior and environmental remodeling...

Harvard Science Book Talk: David Reich (Feb 27 @6:00PM)

Photo of Prof. David Reich and cover of the book "Who We Are and How We Got Here"

In this lecture, Prof. Reich will discuss his new book, Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past.

Congratulations to David Morin and Jacob Barandes!

David Morin and Jacob Barandes named Co-Directors of Undergraduate and Graduate Studies, respectively...

UPCOMING EVENTS

Tuesday, February 19th

MATH:
Start: 03:00pm - End: 03:00pm
- Organizer: Mathematical Picture Language Seminar
- 03:00pm
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CUA Seminar: Dr. Christophe Salomon (Ecole Normale Supérieure)
Start: 04:00pm - End: 05:30pm
- Dual Bose Fermi Superfluids: surprises in the ultracold worldWe will describe the first production and study of a novel quantum system, a mixture of Bose and Fermi superfluids. Such a mixture had long been sought in liquid helium where superfluidity was only achieved separately in bosonic 4He and fermionic 3He. Using dilute quantum gases where interactions can be tuned, we have produced a Bose-Fermi mixture where both species are in the superfluid state [1]. By exciting center of mass oscillations of the mixture we probe the equation of state of the strongly correlated Fermi gas. The superfluid counterflow exhibits very small damping below a certain critical velocity [2]. This velocity is surprisingly high and is compared to a recent theoretical prediction [3]. Finally the lifetime of the Bose-Fermi mixture is governed by a very simple formula involving the fermionic two-body contact [4].[1] Igor Ferrier-Barbut, Marion Delehaye, Sebastien Laurent, Andrew T. Grier, Matthieu Pierce, Benno S. Rem, Frédéric Chevy, Christophe Salomon, A Mixture of Bose and Fermi Superfluids, Science 345, 1035, (2014)[2] M. Delehaye, S. Laurent, I. Ferrier-Barbut, S. Jin, F. Chevy, and C. Salomon, Critical Velocity and Dissipation of an ultracold Bose-Fermi Counterflow, Phys. Rev. Lett., 115, 265303 (2015).[3] Y. Castin, I. Ferrier-Barbut, and C. Salomon, The Landau critical velocity for a particle in a Fermi superﬂuid, Comptes Rendus Physique, 16, 241 (2015). [4] S. Laurent, M. Pierce, M. Delehaye, T. Yefsah, F. Chevy, C. Salomon, Connecting few-body inelastic decay to quantum correlations in a many-body system : a weakly coupled impurity in a resonant Fermi gas, Phys. Rev. Lett., 118, 103403 (2017)
- 04:00pm
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Wednesday, February 20th

Tim Atherton - Tufts
Start: 06:00pm - End: 07:30pm
- 06:00pm
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Thursday, February 21st

ITAMP Lunch Seminar
Start: 12:00pm - End: 01:00pm
- Speaker: Shmuel Bialy (CFA)
- 12:00pm
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CMP Seminar: TBA
Start: 03:00pm - End: 04:00pm
- 03:00pm
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Monday, February 25th

Lawrence Sulak - Boston University
Start: 04:15pm - End: 05:15pm
- 04:15pm
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Tuesday, February 26th

MATH:
Start: 03:00pm - End: 03:00pm
- Organizer: Mathematical Picture Language Seminar
- 03:00pm
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CUA Seminar: Prof. Ben Lev (Stanford University)
Start: 04:00pm - End: 05:30pm
- Many-body cavity QED with multimode resonatorsWe will present our first experiments involving multimode cavity QED, wherein the cavity-mediated atom-atom interaction is dramatically modified compared to that in a single-mode cavity. We demonstrate the engineering of strong, tunable-range, and sign-changing photon-mediated interactions between atoms and between atomic spins. A mechanism for photon-mediated interactions based on the Gouy phases of the cavity modes is introduced and demonstrated. Such interactions can be exploited for the creation of unusual quantum many-body phases. Other results include the observation of a ‘spinor density-wave polariton’ condensate and cavity-assisted dynamical spin-orbit coupling. Together, these results pave the way for future experimental access to nontrivial quantum phases and transitions in driven-dissipative quantum systems, synthetic dynamical gauge fields, and the ability to study nonequilibrium spin glasses and quantum neural networks.
- 04:00pm
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