aspuru-list January 2013

aspuru-list@lists.fas.harvard.edu

29 participants
51 discussions

[Aspuru-Guzik group list] [Aspuru-meetings-list] AMP Seminar Tuesday, January 22, Marko Gacesa, Production and escape of hot H2 and OH molecules from upper planetary atmospheres

by Gonzalo Gonzalez Abad

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 2:00 PM Tuesday, January 22, 2013 Phillips Auditorium 60 Garden St, Cambridge, MA Title: Production and escape of hot H_2 and OH molecules from upper planetary atmospheres Authors: M. Gacesa ( 1(current address), 2 ) and V. Kharchenko ( 2, 3 ) 1 Max Planck Institute for the Physics of Complex Systems, Dresden, Germany 2 ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 3 University of Connecticut, Storrs, CT Abstract Photodissociation of CO_2 and O_2 molecules followed by dissociative recombination of oxygen molecular ions are among the most important sources of hot oxygen atoms in the upper atmospheres of terrestrial planets. The hot oxygen atoms can transfer kinetic energy in collisions with thermal atmospheric gases, perturbing local thermal equilibrium conditions, inducing chemical reactions, and forming rotationally and vibrationally excited products. A specific process of interest in the upper atmospheres of Mars, Earth, and Venus is the reactive collision of hot O atom with a hydrogen molecule, leading to production of rotationally-vibrationally excited H_2 and OH molecules. We present new results of extensive reactive quantum scattering calculations of this process and their implications on the escape of H_2 , HD, and OH molecules from terrestrial planets. Specifically, we calculated molecular escape fluxes for Mars using a simple kinematic model for typical solar conditions. Our results indicate that direct collisional escape of light molecules from terrestrial planets is possible and occurs regularly. This process may play a role in the escape of water from the atmosphere of Mars and similar bodies, and exoplanets. -- -- Gonzalo Gonzalez Abad Atomic and Molecular Physics Division Harvard-Smithsonian Center for Astrophysics 60 Garden Street, MS 50, Cambridge, MA 02138 Phone: 617-496-7938 Email:ggonzalezabad@cfa.harvard.edu _______________________________________________ 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, 3 months

[Aspuru-Guzik group list] Group responsibilities

by Alan Aspuru-Guzik

Dear group members, Please e-mail any group responsibilities you have to Nico, and also he will anonymously list the group responsibilities that are not there but you think should be there. E.g. a group member that brings a laser pointer to every group meeting. If you have ideas like this, send them to Nico and they won't be associated with your name (in other words, you won't be volunteered for that particular activity, unless you want do to so). Please do that by TOMORROW, Alan

11 years, 3 months

[Aspuru-Guzik group list] Fwd: Here it goes

by Cynthia M. Chew

Hi TSTC applicants, We did a random drawing to pick to who would to go to the TSTC Summer school and Ryan and Thomas were selected. Congrats Ryan & Thomas! I've attached video of the drawing for those who need to see it with their own eyes. Best, Cynthia ---------- Forwarded message ---------- From: Aspuru <alan(a)aspuru.com> Date: Tue, Jan 15, 2013 at 11:59 AM Subject: Here it goes To: "aspuru. staff" <aspuru.staff(a)gmail.com> Alan Aspuru-Guzik Associate Professor Harvard University http://aspuru.chem.harvard.edu Sent from my mobile. Please pardon any typos.

11 years, 3 months

[Aspuru-Guzik group list] ITAMP topical lunch discussion: Thursday January 17 @ 12:00

by Mikhail Lemeshko

Dear Friends, On Thursday, January 17, 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: Felipe Herrera Title: Dynamical generation of entanglement in cold molecular gases using strong laser pulses Abstract: Many-particle entanglement can be found in the ground state of natural solids and strongly interacting atomic and molecular gases, but it is still experimentally challenging to generate highly entangled states between weakly interacting particles in a scalable way. In this talk I will describe a one-step method to generate maximally entangled bipartite states with polar molecules in the absence of DC electric fields. For molecules in an optical lattice with site separation of a few micrometers, maximally entangled states can be created using strong off-resonant pulses that are routinely used in molecular alignment experiments. I will present an entanglement measurement scheme based on Bell-type measurements in addressable optical lattices and a global entanglement measure based on traditional microwave spectroscopy. The robustness of the prepared entangled states with respect dissipation induced by optical lattice phonons will also be discussed. If time permits, I will finally overview possible applications of the scheme for quantum information processing and quantum metrology. Looking forward to seeing you there, Misha Lemeshko -- Dr. Mikhail Lemeshko Institute for Theoretical Atomic, Molecular, and Optical Physics (ITAMP) Harvard-Smithsonian Center for Astrophysics MS-14 60 Garden St. Cambridge, MA 02138 U.S.A. mlemeshko(a)cfa.harvard.edu http://sites.google.com/site/mishalemeshko/ Tel. +1 (617) 496-7610 Fax +1 (617) 496-7668

11 years, 3 months

[Aspuru-Guzik group list] visit and group talk of Dr. Alex Eisfeld,

by Semion Saikin

Dear Group, We have Alex Eisfeld visiting us until Thursday, Jan 17. For those who joined the group recently, Alex is a group leader at Max Planck Institute in Dresden. Here is his website http://www.pks.mpg.de/~eisfeld/ .He was staying with our group for about a year and left back to Germany last April. I would strongly suggest new students to talk with Alex. *He will give a group talk on Wednesday, Jan 16, at 4pm in M217* The title of the talk: *Dynamics of a nano-scale rotor driven by single-electron tunneling* *Abstract:* We investigate theoretically the dynamics and the charge transport properties of a rod-shaped nano-scale rotor, which is driven by a similar mechanism as the nanomechanical single-electron transistor (NEMSET). We show that a static electric potential gradient can lead to self-excitation of oscillatory or continuous rotational motion. We identify the relevant parameters of the device and study the dependence of the dynamics on these parameters. We discuss how the dynamics are related to the measured current through the device. Notably, in the oscillatory regime we find a negative differential conductance. The current-voltage characteristics can be used to infer details of the sur- rounding environment which is responsible for damping. ******************************************** Semion K. Saikin, PhD Department of Chemistry and Chemical Biology Harvard University 12 Oxford Street, Cambridge, MA 02138 email: saykin(a)fas.harvard.edu phone: (619)212-6649 ********************************************

11 years, 3 months

[Aspuru-Guzik group list] Monitor Needed (Urgent)

by Marlon Cummings

*Monitor Needed (Urgent)* Dear Group: Are there extra monitors in your area/one that you are not using? If so, please let me know. Best, Marlon ---------------- Marlon G. Cummings Lab Manager, Aspuru-Guzik Group Mallinckrodt M112 Department of Chemistry and Chemical Biology Harvard University 12 Oxford Street Cambridge, MA 02138 617-496-9964 617-496-9411 (fax) http://aspuru.chem.harvard.edu/

11 years, 3 months

[Aspuru-Guzik group list] [IACS-events] 100 Years of Markov Chains: a mini-symposium Weds., Jan. 23

by Rosalind Reid

On Jan. 23, 1913, the first use of the Markov chain was demonstrated in a lecture in St. Petersburg by A. A. Markov. IACS will celebrate the history, intellectual power and 21st-century applications of Markov chains with a trio of talks on Wednesday, Jan. 23. This public event is part of our January ComputeFest. All are welcome to attend. WHAT: 100 Years of Markov Chains, a centenary celebration WHEN: Wednesday, Jan. 23, 9:15 am - 12:15 pm WHERE: 209 Pierce Hall, 29 Oxford Street PROGRAM AND SPEAKER INFORMATION: http://computefest.seas.harvard.edu/markov SPEAKERS: Brian Hayes Senior Writer, American Scientist magazine "First Links in the Markov Chain: Poetry and Probability" Abstract: On January 23, 1913, the Russian mathematician A. A. Markov presented a paper at the Imperial Academy of Sciences in St. Petersburg describing his careful enumerations of vowels and consonants in Alexander Pushkin's poem Eugene Onegin. A century later, the techniques that Markov discussed that day are in daily use everywhere in statistics and scientific computing. We call them Markov chains. On the occasion of this hundredth anniversary I want to consider what motivated Markov's work in this area, and how he came to illustrate his mathematical ideas with an analysis of poetic language. I will go on to discuss a few latter-day applications of Markov chains in linguistics, including the mass production of random prose meant to foil your spam filter. ----- Ryan Prescott Adams Assistant Professor of Computer Science, SEAS "From Markov to Pearl: Conditional Independence as a Driving Principle for Probabilistic Modeling" Abstract: The Markov chain is one of the fundamental abstractions for consideration of stochastic systems. The remarkable insight of Markov was that complex phenomena can be described by the evolution of a "memoryless" system. Markov chain theory has had an enormous impact on probabilistic computation, natural language processing, and information theory, among many other fields. In recent decades, Judea Pearl and others recognized that this notion of "conditional independence" could be used more broadly to define rich classes of probability distributions for complex natural phenomena. I will give an overview of how these ideas connect strongly with graph theory, leading to the concept of a probabilistic graphical model, a centerpiece of modern machine learning and statistics. ----- Pavlos Protopapas Research Associate, Harvard-Smithsonian Center for Astrophysics; Lecturer in Computational Science, SEAS "Applications of Markov Chains in Science" Abstract: The Markov chain and its extension, Markov Chain Monte Carlo, are among the most used algorithms in the sciences. These methods have transformed the way we do science in the last twenty years. In the first part of this talk I will introduce the basic ideas behind these methods and demonstrate them with simple examples: a drunk walking along a pavement, a mutating virus, card shuffling and so on. I will then review applications of Markov chains in various sciences, describing the latest developments and looking toward how Markov's insight might continue to shape computational science in the future. ********************** COMPUTEFEST REMINDERS: SYMPOSIUM: Computing @ Exascale, the Second Annual Symposium on the Future of Computation in Science and Engineering, Friday, Jan. 25, 9:30 am-5 pm, in Maxwell Dworkin G115. Details: http://computefest.seas.harvard.edu/exascale-symposium ONLINE WORKSHOP REGISTRATION for ComputeFest has closed; walk-in registration is welcomed as space is available 15-30 minutes before each workshop. Schedule here: http://computefest.seas.harvard.edu/workshops Signup for this year's STUDENT COMPUTATIONAL CHALLENGE continues through Thursday, Jan. 17. See http://computefest.seas.harvard.edu/student-computational-challenge. Prizes will be presented at the Friday symposium. ----------------- Rosalind Reid Executive Director, Institute for Applied Computational Science Harvard School of Engineering and Applied Sciences Pierce Hall, 29 Oxford Street Cambridge, MA 02138 http://iacs.seas.harvard.edu/people rreid(a)seas.harvard.edu | 617-384-9091 _______________________________________________ Iacs-events mailing list Iacs-events(a)seas.harvard.edu https://lists.seas.harvard.edu/mailman/listinfo/iacs-events

11 years, 3 months

[Aspuru-Guzik group list] Cambridge Commons 8 PM

by Alan Aspuru-Guzik

Dear group members, The committee voted to go to the next stage. That means that the tenure case will be reviewed by the university. This is still not certain, and it is not tenure yet, far from it, but I propose we go and get together to celebrate this stage of the game to the Cambridge commons bar in Mass Avenue at 8 PM. I might be a bit late as I am going home to be with my wife dori and my sons for a while. Best, Alan Alán Aspuru-Guzik | Associate Professor Harvard University | Department of Chemistry and Chemical Biology 12 Oxford Street, Room M113 | Cambridge, MA 02138 (617)-384-8188 | http://aspuru.chem.harvard.edu | http://about.me/aspuru

11 years, 3 months

[Aspuru-Guzik group list] HQOC/ITAMP Special Seminar - 1/16/2013 at 4:00 PM in Lyman 425

by Joan Hamilton

***HQOC/ITAMP Special Seminar*** ***Wednesday, January 16, 2013*** ***4:00 PM, Lyman 425*** Eric Kessler, Max-Planck-Institute for Quantum Optics Dissipative Phase Transitions in Central Spin Systems Abstract: Recent experimental and theoretical developments showed that highly coherent many body physics can emerge even under open system conditions. One prominent example is constituted by the phenomena of dissipative (or dynamical) phase transitions (DPT). In these non-equilibrium situations, distinct quantum phases and transitions with intriguing properties have been reported. However, the theory of DPT is far less developed than in the equilibrium counterpart, i.e. for quantum phase transitions. Against this background, we present an instructive example for DPT in a generic, driven and damped central spin setting. We derive analytically a complete picture of the system's rich steady state phase diagram, which comprises effects like first and second-order phase transitions, as well as regions of bistability, spin squeezing and altered spin pumping dynamics. Further, we discuss the intimate relation between the low excitation spectrum of the Liouville operator and the classification of different transitions, and we consider adaptations of the model for realistic experimental realizations in Nitrogen-Vacancy centers and quantum dots. Refreshments will be served. Joan Hamilton Faculty Assistant to Profs. Greiner & Lukin HQOC Lab Administrator HUCTW Local Union Representative 17 Oxford Street Cambridge, MA 02138 P: 617-496-2544 F: 617-496-2545

11 years, 3 months

[Aspuru-Guzik group list] Congrats to Aidan

by Laszlo Seress

http://www.businessinsider.com/most-impressive-harvard-students-2012-11?op=1 -- Laszlo Ryan Seress Harvard College '14 A.B. Degree Candidate in Chemistry and Physics 1-614-670-2205 323 Cabot Mail Center Cambridge, MA 02138 seress(a)college.harvard.edu

11 years, 3 months

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aspuru-list January 2013