aspuru-list October 2013

aspuru-list@lists.fas.harvard.edu

34 participants
87 discussions

[Aspuru-Guzik group list] Excitonics Seminar - Jeremy Baumberg- Oct 17

by Catherine M Bourgeois

Please post and forward to your group. Thanks. _________________________________ Center for Excitonics Seminar Series Thursday, Oct 17, 2013 3:00 - 4:00 PM RLE HAUS and ALLEN rooms: 36-428 Microcavity Polaritonics: Optically-Steering Interacting Quantum Liquids on a Chip Jeremy Baumberg, Department of Physics, NanoPhotonics Centre, University of Cambridge, UK Abstract: Constructing ultra-high finesse semiconductor microcavities produces quasiparticles called exciton polaritons which can Bose condense even up to room temperature. The resulting macroscopic quantum states are directly visible and allow superflows to be imaged. Spontaneous oscillations, self-organised vortex lattices, and geometrical phase transitions are all part of the rich phenomena observed. Recent references: [1] Nature Physics 8, 190 (2012); G. Tosi et al., "Sculpting oscillators with light within a nonlinear quantum fluid" [2] Nature Communications 3, 1243 (2012); G. Tosi et. al., "Geometrically locked vortex lattices in semiconductor quantum fluids" [3] Science 336, 704 (2012); P. Cristofolini et al., "Coupling Quantum Tunneling with Cavity Photons" [4] Phys.Rev.Lett. (2013); P. Cristofolini et al., "Optical superfluid phase transitions and trapping of polariton condensates Prof. Jeremy J. Baumberg FRS, directs a UK Nano-Photonics Centre at the University of Cambridge and has extensive experience in developing optical materials structured on the nano-scale that can be assembled in large volume. He is also Director of the Cambridge Nano Doctoral Training Centre, a key UK site for training PhD students in interdisciplinary Nano research. Strong experience with Hitachi, IBM, his own spin-offs Mesophotonics and Base4, as well as strong industrial engagement give him a unique position to combine academic insight with industry application in a two-way flow. With over 10000 citations, he is a leading innovator in Nano. This has led to awards of the IoP Young Medal (2013), Royal Society Mullard Prize (2005), the IoP Charles Vernon Boys Medal (2000) and the IoP Mott Lectureship (2005). He frequently talks on NanoScience to the media, and is a strategic advisor on NanoTechnology to the UK Research Councils. He is a Fellow of the Royal Society, the Optical Society of America, the Institute of Physics, and the Institute of NanoTechnology. [see np.phy.cam.ac.uk] Light refreshments will be served. The Center for Excitonics is an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science and Office of Basic Energy Sciences

10 years, 6 months

[Aspuru-Guzik group list] Special group meeting 2-3pm Oct. 16 with postdoctoral candidate

by Suh, Changwon

Dear Group Members, Dr. José Mendoza-Cortés of CALTEC will be visiting our group on October 16 (Wednesday), 2013. He will give us his official talk in the Division room at 2:00 PM that day. His expertises are in artificial photosynthesis, energy storage, fuel cells, and light captures. He is also interested in electronic structure, molecular dynamics, and force field (http://www.jmendoza.caltech.edu). * Please mark your calendar to attend his talk. * Please also let me know if you would like to meet with him on that day. Please respond no later than this Friday before noon. * In addition, I need 2 or 3 people to join for lunch from around 12 (or 12:30) to 1:30. Please respond no later than this Friday before noon. Title: "High-throughput First Principles In Silico Screening to Predict Optimum Band Gap for Light Capture in Solar Fuel Generation and the Porous Framework Genome Project" Abstract: In the first part of the talk we will discuss our approach to finding semiconductors which have an ideal band gap (Eg) in the visible region with maximum e ciency, i.e. Eg around 1.1 eV for H2 generation and Eg of 1.7 to 2.1 eV for O2 generation in a tandem cell. Our project is of high interest for the goals of the Joint Center for Artificial Photosynthesis. More than 1,000 compounds which can have semiconductor properties were automatically screened. The structures were obtained from the Inorganic Structural database (ICSD). We propose a way to determine the properties of the predicted semiconductors which allows us to extrapolate existing data and their correlation.These results pave the way to predict new stable Earth-abundant light absorbers with the precise band gap requirements for water splitting. In the second part of the talk we will discuss Porous Framework Genome Project. Porous frameworks (Metal-Organic and Covalent Organic Frameworks) were constructed by combining secondary building units (SBU), which contain multiple connectors each, with linkers that contain exactly two connectors each. Depending on the amount and orientations of the connectors of each SBU, multiple frameworks can be generated when connecting them together via linkers. An algorithm was created which generates frameworks using every combination of available nets, SBUs, and linkers. Once the frameworks have been created, their energies are minimized to predict the exact atomic structure, and then various computational gas storage simulations are run to predict the framework properties. An online database with 20,000 compounds has been created, which contains the structural data and H2 storage capacity for all these frameworks. Cheers, Changwon

10 years, 6 months

[Aspuru-Guzik group list] [qip] Friday October 11

by Edward Farhi

Hi Quanta We will meet on Friday, tomorrow, at 11:00 in 6-310. Daniel Greenbaum will tell us about what he has been up to. See you there. Best, Eddie ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Edward Farhi Cecil and Ida Green Professor of Physics Director Center for Theoretical Physics 6-300 Massachusetts Institute of Technology Cambridge MA 02139 617 253 4871 ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

10 years, 6 months

[Aspuru-Guzik group list] ITAMP Workshop - October 21-22

by Hamilton, Joan

Dear Colleagues: ITAMP will host a workshop on "Synthesis and Spectroscopy of Large Carbon Molecules" on October 21-22, 2013 at Phillips Auditorium, 60 Garden Street , Cambridge. More information is located at http://www.cfa.harvard.edu/itamp/Large-Carbon-2013.html You're cordially invited to participate in these events by using the registration form from the link above. On the registration form, you should choose to "pay by check", so as to bypass the credit card payment processing. You will not have to pay to attend this workshop. The organizers, Hossein Sadeghpoour Mike McCarthy

10 years, 6 months

[Aspuru-Guzik group list] [IACS-events] IACS Seminar featuring Dmitri "Mitya" Chklovskii on Friday, October 11

by Baker, Natasha

Date: Friday, October 11, 2013 Location: Maxwell-Dworkin G115, 33 Oxford Street, Cambridge, MA 02138 Speaker: Dmitri "Mitya" Chklovskii, Lab Head at Janelia Farm Research Campus, Howard Hughes Medical Institute Time: Informal lunch with speaker, 12:30pm. Talk, 1:00pm Title: How the Brain Handles Big Data: Online Algorithms in Neurons Abstract: Our brains constantly handle big data streamed by our sensory organs. Yet, how this is done in neurons, elementary building blocks of the brain, is not understood. We propose to view a neuron as a signal processing device representing its high-dimensional input by a synaptic weight vector scaled by its output. A neuron accomplishes this task by running two online algorithms: a slow algorithm which adjusts synaptic weights to extract the most non-Gaussian projection of the high-dimensional input, and a fast algorithm which estimates the projection amplitude. Both online algorithms rely on sparsity-inducing regularizers and have provable regret bounds. The steps of these algorithms account for the salient physiological features of neurons such as leaky integration, non-linear output function, Hebbian synaptic plasticity rules, and sparse connectivity and activity. Thus, our work should help model biological neural circuits and develop biologically inspired computing. Speaker bio: Dmitri "Mitya" Chklovskii combines theoretical and experimental tools to reverse engineer the brain. His group reconstructs the brain's wiring diagram and quantitatively formulates neuronal structure-function relationships. ************************* Upcoming IACS Seminars The next IACS seminar will be held on Friday, 10/25 by Mercè Crosas, Director of Data Science, Institute for Quantitative Social Science (IQSS), Harvard Please 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

10 years, 6 months

[Aspuru-Guzik group list] Fwd: Postion Available: University of Alabama Materials Chemistry Search

by Felipe Herrera

Hi everyone, There is a position ad attached for those of you interested in materials science. It seems that they are considering theorists as well. Best, Felipe -------- Original Message -------- Subject: Postion Available: University of Alabama Materials Chemistry Search Date: Wed, 9 Oct 2013 15:39:16 -0700 From: <head(a)chem.ubc.ca> To: <grad(a)chem.ubc.ca>, <faculty(a)chem.ubc.ca>, <reassoc(a)chem.ubc.ca> Hi Everyone, There is an opening for a tenure track assistant professor with expertise in materials science at The University of Alabama. Please see attached. Cheers, Laura Laura Partland Assistant to the Head, Michael Fryzuk Faculty of Science | Department of Chemistry The University of British Columbia | 2036 Main Mall, D225 Phone 604 822-2471 headsec(a)chem.ubc.ca

10 years, 6 months

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

by Ryan Babbush

Hi Everyone, Tomorrow Joey will be giving group meeting at the usual time (2:30) in the usual place (The Division Room). An abstract for his talk is included below. Experimentally determining what a quantum system does, is not straightforward by any means. Even if one can develop an exact picture of the evolution of the system (say using its density matrix) as a function of time, that still does not give you a complete picture of how and when one state evolves into the other: the pathways between all possible states. I will discuss how to get this complete picture (called Quantum Process Tomography) for molecular systems using laser spectroscopy and how one might minimize the experimental errors involved. Then, I will discuss a much simpler method you can use if all you care about is the pathways involving superposition (coherence) persistence. This method, I will show, works with real systems and not just idealized systems as has been shown previously. -- Ryan Babbush | PhD Student in Physics (949) 331-3943 | babbush(a)fas.harvard.edu Harvard University | Aspuru-Guzik Group 12 Oxford Street | 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

10 years, 6 months

[Aspuru-Guzik group list] Pumpkin bread in M-104 next to the 2D printer

by Xavier Andrade

10 years, 6 months

[Aspuru-Guzik group list] Meeting with M. Shapiro 15 minutes earlier at 3 pm

by Felipe Herrera

Hi everyone, There was a last minute change in Moshe Shapiro's schedule and now we are going to meet him at 3 pm instead of 3:15 pm at the Division Room. I hope you can make it. Regards, Felipe On 10/09/2013 10:50 AM, Marlon Cummings wrote: > Hi Felipe: > > 3:15pm in the Division room -- correct? Alan plans to attend. > > MC. > > 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/ > > > On Mon, Oct 7, 2013 at 9:50 AM, Felipe Herrera <faherreraur(a)gmail.com > <mailto:faherreraur@gmail.com>> wrote: > > Dear group, > > I am delighted to announce that this Wednesday at 3:15 pm we will have > Prof. Moshe Shapiro with us at the Division Room. He will be available > for scientific discussion for about 30 min before the HQOC/ITAMP Joint > Quantum Sciences Seminar starts. This is a great opportunity to > discuss > your research with one of the brightest chemical physicists in the > field. Moshe is also a very nice person with a broad interest in > science, so I encourage you to participate in the meeting. > > Moshe Shapiro was a postdoc here in Harvard Chemistry some time ago. > Years later he co-founded the field of coherent control and over the > years has made several contributions to AMO physics as well. For > instance, he invented the now standard method of photo-associating > ultracold atoms to form deeply bound cold diatomic molecules. > Actually, > the department's newest faculty Kang-Kuen Ni used this method to > produce > ultracold KRb molecules back in 2008. > > Best, > > Felipe > _____________________________________________ > Aspuru-list mailing list > Aspuru-list(a)lists.fas.harvard.edu > <mailto:Aspuru-list@lists.fas.harvard.edu> > https://lists.fas.harvard.edu/mailman/listinfo/aspuru-list > >

10 years, 6 months

[Aspuru-Guzik group list] 10/9/2013 - Moshe Shapiro - HQOC/ITAMP Joint Quantum Sciences Seminar -

by Hamilton, Joan

Joint Quantum Sciences Seminar Wednesday | Oct. 9 | 4:00 pm | Jefferson 250 Moshe Shapiro Departments of Chemistry & Physics, University of British Columbia, Canada and Department of Chemical Physics, The Weizmann Institute, Israel "Dark States and the Incoherent Encoding of Molecular Motions" Contrary to conventional wisdom that all dynamics is a result of interference (or “dephasing”) between many (at least 2) energy eigenstates, we show that when a continuum of states is present, even a single molecular eigenstate undergoes “steady-state” quantum dynamics.Moreover, this type of dynamics can be initiated by incoherent (e.g.,solar) light sources. Continua are invariably involved in molecular systems due to a variety of sources such as the ever present bath modes; spontaneously emitted photons; the detachment of electrons; or the dissociation of chemical bonds. Contrary to a single bound energy-eigenfunction which is a real (“standing-waves”) function that carries no flux, hence has no dynamics, a single (complex) continuum energy-eigenfunction carries “steady-state” flux given by the group velocity of the energetically narrow wave packet it represents. We then proceed to discuss the possibility of encoding programmed molecular motions using the above incoherent dynamics. The encoding is attained by ordering the molecular eigenstates to have a specific sequence of "overlapping resonances". Using the prediction we already made in 1972 concerning the formation of "dark states" as a result of interference between overlapping resonances (giving rise to the development of the celebrated "Electromagnetically Induced Transparency" (17 years later), we show how "dark states" give rise to a very efficient transfer between eigenstates, thereby executing a desired sequence of molecular events (such as that involved in protein folding). We also show that "dark states" may enable us to attain the "holy grail" of chemical dynamics: the production of a molecular beams containing just one pre-selected internal (vib-rotational) state. Student Presentation by Jarrod McClean (Aspuru-Guzik Lab) at 4:00 PM Coffee and Tea Reception at 4:10 PM Guest Presentation at 4:30 PM

10 years, 6 months

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aspuru-list October 2013