aspuru-list May 2015

aspuru-list@lists.fas.harvard.edu

17 participants
48 discussions

[Aspuru-Guzik group list] Fwd: AAG Temporary Employee

by Marlon Cummings

Dear group: We are seeking a part-time temporary employee (20-25 hours/week) to work in our office in for approximately 3 months beginning on May 18th or 26th. If you know of a professional that is reliable, has the skills, and is able to work in a fast-paced office environment, please forward and have them send us their CV. I've attached the role and qualifications. Thanks, Marlon. --------------- Marlon G. Cummings Lab Manager, Aspuru-Guzik Group Mallinckrodt M136 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/

8 years, 12 months

[Aspuru-Guzik group list] [qip] 6.435 in Fall Term 2015

by Jeffrey H Shapiro

Hi QIP community, I have prevailed upon EECS to let me offer 6.453, Quantum Optical Communication, in Fall 2015, whereas previously its next offering would have been in Fall 2016. I have attached an extract from the Fall 2015 on-line subject listing that describes the subject. Anyone potentially interested in taking the class who wants more information about it should contact me. Best regards, Jeff Shapiro ************************************************ Jeffrey H. Shapiro Julius A. Stratton Professor of Electrical Engineering Massachusetts Institute of Technology Room 36-517 Cambridge, MA 02139-4307 Phone: 617-253-4179 Fax: 617-324-3633 email: jhs(a)mit.edu<mailto:jhs@mit.edu> ************************************************ _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

8 years, 12 months

[Aspuru-Guzik group list] [Aspuru-meetings-list] Special Group meeting, Thursday, Div. Room, 2:30pm

by Jennifer Wei

Hi everyone, This week, on May 7th, we have a special group meeting given by Dr. Justin Caram from MIT. Please see below for the title and abstract of his talk. Cheers, Jennifer ------------------------------ Title: Long-Range Excitonic Transport in Double-Walled J-Aggregates/ Ensemble Methods in Single Molecule Microscopy I will discuss two different topics: 1) Creating circuit elements which conduct excitons instead of charge, and 2) using the intrinsic coherence length of light to study spectral dynamics. 1) Due to their long-range order, large domain sizes and high oscillator strengths, one-dimensional tubular J-Aggregates can be used as the excitonic equivalent of a wire. However, photochemical instability has hindered the study of these materials and their implementation in practical devices. In this talk, I demonstrate cyanine based J-aggregates which are stabilized against photobleaching and cryogenic damage in a sugar-based matrix. I probe the temperature dependent absorption and emission of these aggregates, and signatures of exciton-exciton annihilation at low photon fluxes. I demonstrate micron scale one-dimensional exciton diffusion lengths at room temperature, and band-like transport as we tune dynamic disorder in the system. This distance is among the longest exciton diffusion distances ever measured for an organic supramolecular system. 2) Colloidal nanostructures show size, shape and surface heterogeneity. This structural diversity leads to significant variation in optical and photochemical properties, such as blinking, lifetimes, and exciton/biexciton dynamics — even within a single colloidal preparation. Both ensemble and single molecule spectroscopic approaches can elucidate this heterogeneity but often rely on selective data acquisition and modeling. We have developed new approaches to study single quantum dot properties under very weak excitation conditions, and in solution, extracting single dot spectral lineshapes, and exciton/biexciton interactions. To accomplish this, we combine the fluorescent correlation spectroscopy (FCS) with Fourier Spectroscopy, utilizing the intrinsic coherence length of emission to encode an FCS trace with spectral information. We use Solution Photon Correlation Fourier Spectroscopy (S-PCFS), probes the intrinsic linewidths of a variety of new materials and structures, including colloidal quantum rods, nanoplatelets and quantum confined NIR emitting nanocrystals, elucidating new spectral dynamics in these systems. This work can then inform the synthetic community on how best to optimize these properties. I will present new results about PbS nanoparticle lineshapes in solution, which describe how these systems can be optimized and how to use them for photochemical and photovoltaic applications. This looks like a lot, but the each topic should be about 20 minutes. _______________________________________________ Aspuru-meetings-list mailing list Aspuru-meetings-list(a)lists.fas.harvard.edu https://lists.fas.harvard.edu/mailman/listinfo/aspuru-meetings-list

8 years, 12 months

[Aspuru-Guzik group list] Joint P-Chem/Excitonics Seminar - TODAY!. 4:30 PM in 4-370

by Catherine M Bourgeois

TODAY! Please post and forward to your group(s). Joint Seminar: Physical Chemistry and Center for Excitonics Navigating Space-Time with Ultrafast Exciton Photolithography or Scintillating Near-fields to Follow Dynamic Processes in Molecular Materials May 5, 2015 at 4:30pm/ rm: 4-370 Naomi Ginsberg University of California/Department of Chemistry and Physics [nsginsberg] abstract: A cross-cutting theme in my research group is to examine dynamic processes in spatially-heterogeneous condensed phase molecular materials over a wide range of time scales. I will share recent results in multiple areas, all underpinned by the strong correlation between physical structure and the optical properties of materials. Our investigations often require tailoring the spatial and temporal resolution of our measurement approaches. I will explain how by measuring the ultrafast electronic properties of heterogeneous, ‘printed’ semiconducting films of small organic molecules we infer the much slower dynamics by which complex nanoscale structural motifs in the films emerge when they self-assemble in an evaporating solvent. These studies reveal the generation of non-equilibrium nanoscale structures that arise from coupling the dynamics of fundamental phase transformation processes of solute crystallization with solvent evaporation. They also pinpoint the challenges associated with developing high carrier mobility materials for printed plastic electronics. The migration of Frenkel excitons, tightly-bound electron-hole pairs, in organic and hybrid organic-inorganic semiconducting films is critical to the function of many next generation optoelectronic devices. While these materials can exhibit a high degree of structural heterogeneity on the nanoscale, traditional measurements of exciton diffusion lengths are performed on bulk samples. Since both the characteristic length scales of structural heterogeneity and the reported bulk diffusion lengths are typically smaller than the optical diffraction limit, I will describe how we adapt far-field super-resolution fluorescence imaging to determine in-situ exciton diffusivities and to uncover the correlations between the structural and energetic landscapes that the excitons explore. Motivated by the need to observe the dynamics of biomolecular interactions on their characteristic length scales, I will also show how we have appropriated the nanoscale resolution of electron microscopy and the near-field luminescence properties of scintillating oxide films to non-invasively image soft materials that cannot be interrogated directly with a damaging electron beam. In addition to focusing on soft materials in organic electronics and biology, I will also demonstrate this new imaging modality applied to plasmonic nanostructures. bio: Naomi Ginsberg received a B. A. Sc. from the University of Toronto (Engineering Science) (2000) and a Ph.D. from Harvard University with the Physics – Hau group (2007). From 2007 – 2010, she was a Postdoctoral Fellow in the Physical Biosciences Division-Fleming group at the Lawrence Berkeley National Laboratory. Awards include UC Berkeley Department of Chemistry Teaching Award (2013), DARPA Young Faculty Awardee (2012), Packard Fellow for Science and Engineering (2011), and Cupola Era Endowed Chair in the College of Chemistry (2010-2012). Her group focuses on visualizing ultrafast energy flow in natural and artificial light harvesting systems and on combining electron and optical microscopies to facilitate high-resolution studies of living things and molecular interactions in solution. Naomi’s background in chemistry, physics, and engineering has led her to observe coherent and previously obscured energy transfer in light harvesting complexes from plants, to develop polarization techniques in ultrafast multidimensional spectroscopy to extract structure from electronically-coupled systems, to slow, stop, and store light pulses in some of the coldest atom clouds on Earth, and to discover, follow, and understand the interactions of superfluid nonlinear excitations.

8 years, 12 months

[Aspuru-Guzik group list] Joint P-Chem/Excitonics Seminar - Tomorrow. May 5, 4-370

by Catherine M Bourgeois

Please post and forward to your group(s). Joint Seminar: Physical Chemistry and Center for Excitonics Navigating Space-Time with Ultrafast Exciton Photolithography or Scintillating Near-fields to Follow Dynamic Processes in Molecular Materials May 5, 2015 at 4:30pm/ rm: 4-370 Naomi Ginsberg University of California/Department of Chemistry and Physics [nsginsberg] abstract: A cross-cutting theme in my research group is to examine dynamic processes in spatially-heterogeneous condensed phase molecular materials over a wide range of time scales. I will share recent results in multiple areas, all underpinned by the strong correlation between physical structure and the optical properties of materials. Our investigations often require tailoring the spatial and temporal resolution of our measurement approaches. I will explain how by measuring the ultrafast electronic properties of heterogeneous, ‘printed’ semiconducting films of small organic molecules we infer the much slower dynamics by which complex nanoscale structural motifs in the films emerge when they self-assemble in an evaporating solvent. These studies reveal the generation of non-equilibrium nanoscale structures that arise from coupling the dynamics of fundamental phase transformation processes of solute crystallization with solvent evaporation. They also pinpoint the challenges associated with developing high carrier mobility materials for printed plastic electronics. The migration of Frenkel excitons, tightly-bound electron-hole pairs, in organic and hybrid organic-inorganic semiconducting films is critical to the function of many next generation optoelectronic devices. While these materials can exhibit a high degree of structural heterogeneity on the nanoscale, traditional measurements of exciton diffusion lengths are performed on bulk samples. Since both the characteristic length scales of structural heterogeneity and the reported bulk diffusion lengths are typically smaller than the optical diffraction limit, I will describe how we adapt far-field super-resolution fluorescence imaging to determine in-situ exciton diffusivities and to uncover the correlations between the structural and energetic landscapes that the excitons explore. Motivated by the need to observe the dynamics of biomolecular interactions on their characteristic length scales, I will also show how we have appropriated the nanoscale resolution of electron microscopy and the near-field luminescence properties of scintillating oxide films to non-invasively image soft materials that cannot be interrogated directly with a damaging electron beam. In addition to focusing on soft materials in organic electronics and biology, I will also demonstrate this new imaging modality applied to plasmonic nanostructures. bio: Naomi Ginsberg received a B. A. Sc. from the University of Toronto (Engineering Science) (2000) and a Ph.D. from Harvard University with the Physics – Hau group (2007). From 2007 – 2010, she was a Postdoctoral Fellow in the Physical Biosciences Division-Fleming group at the Lawrence Berkeley National Laboratory. Awards include UC Berkeley Department of Chemistry Teaching Award (2013), DARPA Young Faculty Awardee (2012), Packard Fellow for Science and Engineering (2011), and Cupola Era Endowed Chair in the College of Chemistry (2010-2012). Her group focuses on visualizing ultrafast energy flow in natural and artificial light harvesting systems and on combining electron and optical microscopies to facilitate high-resolution studies of living things and molecular interactions in solution. Naomi’s background in chemistry, physics, and engineering has led her to observe coherent and previously obscured energy transfer in light harvesting complexes from plants, to develop polarization techniques in ultrafast multidimensional spectroscopy to extract structure from electronically-coupled systems, to slow, stop, and store light pulses in some of the coldest atom clouds on Earth, and to discover, follow, and understand the interactions of superfluid nonlinear excitations.

8 years, 12 months

[Aspuru-Guzik group list] Wednesday, May 6, Special HQOC Seminar: Rivka Bekenstein 4PM (Lyman 425)

by Coleman, Karl

There will be a Special HQOC Seminar on Wednesday, May 6, at 4 PM in Lyman 425. Rivka Bekenstein will be visiting from Technion, Israel Institute of Technology, and will present the following talk: General Relativistic Phenomena in Optical Settings (see attached flyer for more details). Rivka is also available for meetings and lab tours. Theorists, in particular, may be interested and can schedule appointments by signing up using the following link: https://docs.google.com/a/g.harvard.edu/spreadsheets/d/1tAVgwJuPCdRvDUsq7Mr… Karl Karl Coleman HQOC Laboratory Administrator Faculty Assistant to Profs. Greiner and Lukin Harvard University Department of Physics 17 Oxford Street Cambridge, MA 02138 P: (617) 496-2544 F: (617) 496-2545

8 years, 12 months

[Aspuru-Guzik group list] group pictures this week after group meeting

by Joey Goodknight

Hello All, Group pictures will happen after group meeting on Thursday as I received minimal reasons to not do it this week. Please come to group meeting at 2:30 if you can, at your most photogenic and we'll start photographing at roughly 3:30. I'm sorry to those of you who won't be here; with a group this big, it's virtually impossible to insure everyone will be at the same place any given time :( We're almost certainly going to go outside to take the picture, just FYI Have a great week! -Joey

8 years, 12 months

[Aspuru-Guzik group list] 5K

by Alan Aspuru-Guzik

Dear all, Jacob and I have just signed up for a 5K. YOHOO. If anybody wants to sign up, here is the link: Saturday May 16th, 10 AM (Bib pickup 8.30-9.30 AM). It is in Millis, MA. I imagine we could carpool there. http://rcm.nu/1JKkdCm It would be fun to have a group contingent. This is random 5K for a Montessori School, so let's create a Harvard Contingent... We could try to sign up for other 5Ks periodically. Sorry that it is not closer to the campus, next time we will try to be in Cambridge, etc. Alan Alán Aspuru-Guzik | Professor of Chemistry and Chemical Biology Harvard University | 12 Oxford Street, Room M113 | Cambridge, MA 02138 (617)-384-8188 | http://aspuru.chem.harvard.edu | http://about.me/aspuru

8 years, 12 months

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aspuru-list May 2015