aspuru-list January 2013

aspuru-list@lists.fas.harvard.edu

29 participants
51 discussions

[Aspuru-Guzik group list] Free black vinyl couch-bed with 3 storage drawers

by Aspuru

Dear group members, Dori and I are rearranging furniture at home and will not need this couch-bed anymore. It cost us originally 500 back in the bay area circa 2005. We used to have it in our living room when I was a postdoc. It is well preserved and has great storage drawers. It is *free* to the first group member that agrees to come to my house (Cambrigeport) and take it away before next Saturday when we have other furniture come in. It is great as a guest bed! I will send another picture of it in the next message. Again, first come, first-serve. Alan Aspuru-Guzik Associate Professor Harvard University http://aspuru.chem.harvard.edu Sent from my mobile. Please pardon any typos.

9 years, 11 months

[Aspuru-Guzik group list] [Aspuru-meetings-list] Holger Müller's visit to CfA, Monday, Feb 4 (aspuru-meetings-list@lists.fas.harvard.edu)

by Gang Li (Google Drive)

I've shared an item with you: Holger Müller's visit to CfA, Monday, Feb 4 https://docs.google.com/spreadsheet/ccc?key=0AhQgs5Zq9lQ9dFhTNUtDSGoxNFBlTl… It's not an attachment -- it's stored online at Google Docs. To open this document, just click the link above. Dear colleagues, A gentle reminder. Holger Müller from UC Berkeley is visiting CfA and he will talk about 'Matter-wave clocks' on the coming Monday morning 11:00-12:00AM. He will arrive this Saturday and leave on Monday evening. If you want to meet with him, could you add your name in the spreadsheet? Thank you. Best Regards, Gang _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list

11 years, 2 months

[Aspuru-Guzik group list] [Aspuru-meetings-list] AMP Seminar, 11:00 AM, Monday, Feburary 4, Holger Müller, Matter-wave clocks

by Gang Li

A gentle reminder… Please join us for a seminar sponsored by the Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics. Complete schedule at http://www.cfa.harvard.edu/amp/events.html 11:00 AM Monday, February 4, 2013 Phillips Auditorium 60 Garden St, Cambridge, MA Title: Matter-wave clocks Author: Holger Müller Matter-wave clocks Holger Müller, UC Berkeley It is a key principle of quantum mechanics that plane matter waves are proportional to exp(-ipμxμ/ℏ)=exp(-iω0τ), where pμ and xμ are respectively 4-momentum and position, and τ is the proper time measured along the particle’s trajectory. Thus, the quantum state of a free particle of mass m accumulates the same phase as a clock ticking at the particle’s Compton frequency of ω0=mc2/ℏ travelling along the particle’s trajectory. This implies that a single particle can be a reference for a clock. In principle, such a clock could be built by annihilating particle-antiparticle pairs and counting the frequencies of the generated photons. This would provide a frequency reference with virtually infinite quality factor Q and unsurpassed stability against systematic influences. The frequency (ω0/2π=3×1025 Hz for a Cesium atom), however, is far beyond modern counting techniques. A method to divide it into a technically accessible range is thus required. We demonstrate a “Compton clock,” a clock referenced to ω0, using an optical frequency comb to self-reference a Ramsey-Bordé atom interferometer and synchronize an oscillator at a subharmonic of ω0 . The interferometer is based on n-photon Bragg diffraction. It is self-referenced by locking the laser to the Nth multiple of the measured recoil frequency. The clock’s frequency ωm=ω0/(2nN2) is then fully determined by ω0 and the known numerical factors N2 and n. The clock has an accuracy and stability of 4×10-9. It highlights the intimate connection between frequency and mass: The Compton frequency can serve as a frequency reference directly, without requiring the particle to be annihilated. It allows measurement of microscopic masses with 4×10-9 accuracy in the proposed revision to SI units. Together with the Avogadro project, it yields calibrated kilograms. We will survey other applications of matter waves as clocks, such as testing relativity and verifying the gravitational Aharonov-Bohm effect. Reference: A clock directly linking time to a particle’s mass. Shau-Yu Lan, Pei-Chen Kuan, Brian Estey, Damon English, Justin Brown, Michael Hohensee, and Holger Müller, Science, <http://dx.doi.org/10.1126/science.1230767> http://dx.doi.org/10.1126/science.1230767 (2013). Regards, Gang ************************** Gang Li Post-doctoral fellow Atomic and Molecular Physics Division Harvard-Smithsonian Center for Astrophysics Cambridge USA Tel: 6174962593 _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list

11 years, 2 months

[Aspuru-Guzik group list] [IACS-events] IACS spring seminars start Feb. 8; other events of interest

by Info, IACS

Dear friends, IACS is pleased to announce that the spring IACS Seminars series will begin Friday, Feb. 8, with a presentation on "Exploring Energy Landscapes: From Molecules to Nanodevices" given by David Wales, University Professor of Chemical Physics at the University of Cambridge. IACS Seminars will take place on Fridays in room G125 Maxwell Dworkin (33 Oxford St., Cambridge). Lunch is served at 12:30, and the talk begins at 1 pm. Abstract: In molecular science, a computational framework for investigating structure, dynamics and thermodynamics can be provided by coarse-graining a potential energy surface into the basins of attraction of local minima. Steps between local minima form the basis for global optimisation and for calculating thermodynamic properties. To treat global dynamics, we must include transition states of the potential energy surface. These link local minima via steepest-descent paths. We may then apply discrete path sampling, which provides access to rate constants for rare events. In large systems the paths between minima with unrelated structures may involve hundreds of stationary points of the potential energy surface. New algorithms have been developed for both geometry optimization and finding connections between distant local minima. Applications will be presented for a range of different examples, including atomic and molecular clusters, biomolecules, condensed matter, and coarse-grained models of mesoscopic structures. Speaker bio: David Wales is University Professor of Chemical Physics and Deputy Head of the Department of Chemistry at the University of Cambridge. Author or co-author of 301 research papers and two books, he is interested in energy landscapes and their applications to chemical biology, spectroscopy, clusters, solids and surfaces. Wales earned his bachelor's degree and PhD in chemistry at Cambridge and subsequently conducted postdoctoral research as a Lindemann Trust Fellow, Lloyd's of London Tercentenary Fellow, Royal Society Research Fellow and Research Fellow of Downing College before being named University Lecturer in 1998. He is a Fellow of the Royal Society of Chemistry and winner of the Society's Meldola Medal and Prize. He has been a Visiting Professor at Harvard, the French universities of Paris-Sud, Paul Sabatier and Lyon, and Boston University. He recently chaired the inaugural Energy Landscapes Meeting convened by the European Science Foundation. Homepage: http://www-wales.ch.cam.ac.uk *********** The following events during the coming week are also of possible interest: --EEHPC@MIT, Friday, Feb. 1 http://meegs.mit.edu/ --Database Summit, Friday, Feb. 1 http://db.csail.mit.edu/nedbday13/ --Presentation by David Keyes on graduate programs at KAUST, Monday, Feb. 4, noon-2 pm, Maxwell Dworkin G125 *********** Mark your calendar for the following additional spring seminars: --Feb. 15: Peter Der Manuelian, Philip J. King professor of Egyptology, Harvard FAS --Feb. 22: Boyce Griffith, Medicine and Mathematics, Courant Institute, NYU --March 1: John Quackenbush, professor of computational biology and bioinformatics, Harvard School of Public Health --March 8: David H. Rogers, computational physical chemist, Sandia National Laboratories --March 15: Mark Kramer, assistant professor of mathematics, Boston University --March 29: Jeff Hammerbacher, chief scientist, Cloudera --April 12: Miriah Meyer, assistant professor, School of Computing/Scientific Computing and Imaging Institute, University of Utah --April 26: Franziska Michor, associate professor of biostatistics and computational biology, Dana-Farber Cancer Institute Students interested in these seminars should note that we are launching a new course this semester based on the series: Applied Computation 298r, Interdisciplinary Seminar in Computational Science and Engineering, taught by Efthimios Kaxiras and Daniel Weinstock. The first meeting is Friday, Feb. 1, at noon in Maxwell Dworkin 323. ********** Visit http://iacs.seas.harvard.edu/events to subscribe to our Google calendar, manage your subscription to this mailing list, or access video and audio recordings of previous seminars. _______________________________________________ Iacs-events mailing list Iacs-events(a)seas.harvard.edu https://lists.seas.harvard.edu/mailman/listinfo/iacs-events

11 years, 2 months

[Aspuru-Guzik group list] [Aspuru-meetings-list] group meeting tomorrow: Joey Goodknight

by Ryan Babbush

Hello Everyone, After getting feedback about when people can make it to group meeting, we have officially decided to move group meeting this term to 3:00pm - 4:00pm (or 4:30pm depending on meeting length). This next part is confusing: we will not start having group meetings at this new time until 2/15. On 2/8 we will have group meeting at an anomalous time (1:30-2:30). Tomorrow, we will have our last group meeting at the old time of 2:30. All meetings will still be in the Division room. If any of this is confusing, please see the calendar which I have recently updated. Tomorrow, Joey Goodknight will present his research on spectroscopy. An abstract is provided below. ======================= Experimentalists who practice electronic spectroscopy need a tool to determine whether or not the excited states of two adjacent molecules are coupled. More specifically, they need an unambiguous tool to show that when the molecules are excited with light, that this coupling begets a superposition between the two excited states (a coherence) which lasts an appreciable amount of time. Having such a tool to determine the existence of a long-lived electronic coherence would allow for the resolution of certain controversies in quantum biology regarding chlorophyll coherences and would be a highly useful tool to guide future efforts towards developing artificial molecular (excitonic) circuits. In this talk, I will discuss a possible experimental methodology for being able to make this determination of long-lived electronic coherences, where we know it theoretically works and where it might not work and how we plan to go about testing it. -- Ryan Babbush | PhD Student in Chemistry (949) 331-3943 | babbush(a)fas.harvard.edu Harvard University | Aspuru-Guzik Research Group 12 Oxford Street, Box 400 | Cambridge, MA 02138 _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list

11 years, 2 months

[Aspuru-Guzik group list] [qip] Friday

by Edward Farhi

Hi Quanta Please do let me know if you will be coming on Friday so we can figure out how much pizza to get! Best, Eddie _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

11 years, 2 months

[Aspuru-Guzik group list] Hongjie Dai

by Alan Aspuru-Guzik

Dear group members, Professor Hongjie Dai from Stanford was supposed to meet with me at 9.15 today. Any volunteers to meet with him outside my office? I was under the weather with chills all night and prefer not to come today to recover. Please tell Helen if you can make it. I hope somebody sees this early and can tell Hongjie about your research and apologize for me Thanks! Alan -- Alan Aspuru-Guzik Associate Professor of Chemistry and Chemical Biology Harvard University http://aspuru.chem.harvard.edu

11 years, 2 months

[Aspuru-Guzik group list] Cancellation ITAMP topical lunch discussion Thursday January 31st

by Charles Mathy

Dear friends, The ITAMP lunch topical discussion of Thursday January 31st has been cancelled. I would also like to point your attention to a talk taking place at Lyman. Richard Schmidt - Technical university of Munich Title: Functional RG for cold atoms: from few-body Efimov to many-body Polaron physics Place: Lyman 425 Physics Date/Time: Thursday Jan 31/ 2013 , 12:00- 1:00 PM Sincerely, Charles

11 years, 2 months

[Aspuru-Guzik group list] [qip] Friday

by Edward Farhi

Hi Quanta We will meet on Friday at 11:00 to hear from our friends who went to China. Also since Scott just produced his very best result, we will celebrate with a pizza lunch. So let me know if you will be coming on Friday. Best, Eddie ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Edward Farhi Cecil and Ida Green Professor of Physics Director Center for Theoretical Physics Massachusetts Institute of Technology 6-300 Cambridge MA 02139 617 253 4871 ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

11 years, 2 months

[Aspuru-Guzik group list] ITAMP topical lunch discussion: Thursday January 31st @ 12:00

by Charles Mathy

Dear Friends, On Thursday, January 31st, there will be an ITAMP topical lunch discussion. Tea Room (P-226) @ CfA (60 Garden Street) Time: 12:00-1:30 As always pizza will be served. Speaker: Matthias Punk Title: Mobile impurity near the superfluid-Mott insulator transition in two dimensions Abstract: In this talk I'm going to discuss transport properties of an impurity atom coupled to bosons in a 2d optical lattice at integer filling near the superfluid-Mott insulator transition. Calculating transport coefficients near quantum critical points remains a challenging problem in theoretical condensed matter physics, and I will start the talk by giving an overview of the basic problems and open questions in this field. After that I'm going to focus on the impurity diffusion constant, which can be measured directly in experiments with quantum gas microscopes, and which exhibits some unexpected properties near the superfluid-Mott insulator critical point. Looking forward to seeing you there, Charles Mathy

11 years, 2 months

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aspuru-list January 2013