aspuru-list April 2018

aspuru-list@lists.fas.harvard.edu

15 participants
40 discussions

[Aspuru-Guzik Group List] [Friday, April 27th at 10:30 AM] Felix's Going Away Breakfast

by Siria Serrano

Dear Group, Join me in the Division Room next Friday at 10:30 AM to celebrate Felix's time as our Lab Admin. and to wish him well. We'll be reminiscing about all the candy we ate thanks to him and he might even give us a few tips on prize-winning step counts! There will be breakfast. Cheers, Siria -- *Siria Serrano* *Faculty Assistant* *Aspuru-Guzik Group* *Harvard University **Department of Chemistry and Chemical Biology* *12 Oxford St. M 136* *Cambridge, MA 02138* *P:** (617) 496-1716 <%28617%29%20496-1716>** F: **617-496-9411 <617-496-9411>*

6 years

[Aspuru-Guzik Group List] Excitonics Seminar: TODAY @2:45PM, RLE 36-428

by Catherine M Bourgeois

TODAY AT 2:45 PM! Please post and forward to your groups (Poster attached), thank you. Center for Excitonics presents: Polymer-Acceptor Bulk Heterojunction Solar Cells: From Chemical Structure to Packing and Efficiency April 17, 2018 at 2:45 PM/36-428 Jean-Luc Bredas Department of Chemistry and Biochemistry, Georgia Tech [http://www.rle.mit.edu/excitonics/wp-content/uploads/2017/08/Jean-luc-Breda…] The morphology of the active layer of a bulk heterojunction (BHJ) solar cell, made of a blend of an electron-donating polymer and an electron-accepting fullerene or nonfullerene derivative, is known to play a determining role in device performance. Here, based on the results of molecular dynamics simulations and long-range corrected density functional theory calculations, we first describe the nature of the binding interactions at the donor�Cacceptor interfaces, the molecular-level packing in the pure phases as well as at these interfaces, and the impact of the system dynamics on the interfacial electronic structure. We then discuss how even minor changes in the chemical structure of the polymer backbone have been shown experimentally to change substantially the blend morphology and the resulting solar-cell efficiency. Taking a series of representative systems based on benzothiadiazole-quaterthiophene polymers and PC71BM, we elucidate the impact of the chemical changes on the ��local�� morphology. We focus on the extent of polymer-fullerene mixing, on their packing, and on the characteristics of the fullerene-fullerene connecting network in the mixed regions, which are all aspects that are difficult to access experimentally. We are able to rationalize the evolutions in power conversion efficiencies within the polymer series. Finally, we address the peculiarities observed in the PIPCP-fullerene blends. This work is supported by the Office of Naval Research, namely in the framework of the MURI Center on Advanced Organic Photovoltaics. Jean-Luc Br��das is a Belgian chemist and currently at Georgia Tech. He was a Distinguished Professor of Material Science and Engineering in the Physical Science and Engineering Division at KAUST, and at the Universit�� de Mons-Hainaut Belgium. He studied Chemistry (B.S. 1976) and obtained a PhD in 1979 at the Facult��s Universitaires Notre-Dame de la Paix (University of Namur), Belgium. His research deals with the structural, electronic, and optical properties of novel organic and nanomaterials with promising characteristics in the field of electronics, photonics, and information technology. Br��das is among the top 100 most cited chemists in the world, and is included in the list of the Highly Cited Researchers for Chemistry [2]. He is the Director of International Programs at the Center for Organic Photonics and Electronics at Georgia Tech. He is a member of the International Academy of Quantum Molecular Science (2011).[1] He is a Fellow of the American Association for the Advancement of Science, the American Chemical Society, the American Physical Society, and the Optical Society of America. 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

6 years

[Aspuru-Guzik Group List] Selecting time to take a group photo

by Mendoza, Douglas

Dear all, Please fill out the following doodle poll to determine the best time to take a group photo within the next 2 weeks. The photo should not take more than 10mins Times range from 11am to 4pm on 15mins intervals. Check your calendar to see your availability. https://doodle.com/poll/bc2xygfmtzarh5ez Instructions: -Click the link below and press the plus sign next to "participants" to add your name. I suggest filling out the survey using Calendar format by clicking the tap "Calendar" that is next to "table" (you could also fill it out using the table format, but I found it a little tedious) Sorry if the survey is a bit long, but we'd like to choose a convenient time when most of us are around https://doodle.com/poll/bc2xygfmtzarh5ez Thank you, Douglas

6 years

[Aspuru-Guzik Group List] ITAMP/HQOC student&postdoc lunch

by Hannes Pichler

Dear students and postdocs, tomorrow, Wednesday, November 15th, we will take this week’s ITAMP/HQOC speaker Tongcang Li out for lunch at Russel House Tavern. If you would like to join, please sign up via the following link (limited to 8 people): https://docs.google.com/spreadsheets/d/1aY3B6-XNLVZFr6iX502cG36IuJ7IFTKp6Pf… We meet at LISE cafe at 11:40. Best, Hannes

6 years

[Aspuru-Guzik Group List] ITAMP lunch seminar - Thomas Christensen, MIT (April 19th)

by Bekenstein, Rivka

*ITAMP Lunch Seminar* *Speaker: *Thomas Christensen (MIT) *Date:* Thursday, April 19th *Time:* 12:00-1:00 pm Includes Pizza. *Title: Non-conventional surface and edge effects in plasmonics* *Abstract: *I will discuss some recent work, which exemplify aspects of plasmonics that broadly fall under the category of non-conventional electronic and optical interface effects. Quantum corrections in nanoplasmonics [1] exemplifies the former aspect; for structural feature-sizes or resonant wavelengths approaching the few-nanometer regime, the conventional, local description of electromagnetics breaks down due to its omission of electronic spill-out, surface-enabled Landau damping, and nonlocality. In noble metals, a hydrodynamic model provides a decent effective remedy to the conventional approach, e.g. reproducing experimentally measured blueshifts and regularizing several singular limits of the conventional approach. Though popular and physically transparent, however, the hydrodynamic model is not a generic remedy due to its neglect of spill-out and surface-enabled Landau damping. I will discuss how a recently developed framework, based on the so-called Feibelman *d*-parameters, allows an general, analytical, and straightforward account of all surface-related corrections with TDDFT-level accuracy. Finally, I will discuss our recent work on the prediction of high-frequency topological plasmonic edge modes in structured graphene under a magnetic bias [2] as well as the experimental measurement of low-frequency topological magnetoplasmonic edge modes in the 2D electron gas of a hetero-junction. [1] T. Christensen, W. Yan, A.-P. Jauho, M. Soljačić, & N.A. Mortensen, *Quantum corrections in nanoplasmonics: shape, scale, and material*, Phys. Rev. Lett. *118*, 157402 (2017) [2] D. Jin*, T. Christensen*, M. Soljačić, N.X. Fang, L. Lu, & X. Zhang, *Infrared topological plasmons in graphene*, Phys. Rev. Lett.118, 245301 (2017) *Location: *B-106 @ Center for Astrophysics (60 Garden Street) *Directions: *After entering the lobby of the CfA, turn right to enter the hallway of the B building. In the hallway, turn right again, B-106 will be at the end of the hallway on the left side.

6 years

[Aspuru-Guzik Group List] TIME CHANGE: Excitonics Seminar: TOMORROW April 17@2:45PM, RLE 36-428

by Catherine M Bourgeois

PLEASE NOTE TIME CHANGE to 2:45 PM Please post and forward to your groups (Poster attached), thank you. Center for Excitonics presents: Polymer-Acceptor Bulk Heterojunction Solar Cells: From Chemical Structure to Packing and Efficiency April 17, 2018 at 2:45 PM/36-428 Jean-Luc Bredas Department of Chemistry and Biochemistry, Georgia Tech [http://www.rle.mit.edu/excitonics/wp-content/uploads/2017/08/Jean-luc-Breda…] The morphology of the active layer of a bulk heterojunction (BHJ) solar cell, made of a blend of an electron-donating polymer and an electron-accepting fullerene or nonfullerene derivative, is known to play a determining role in device performance. Here, based on the results of molecular dynamics simulations and long-range corrected density functional theory calculations, we first describe the nature of the binding interactions at the donor�Cacceptor interfaces, the molecular-level packing in the pure phases as well as at these interfaces, and the impact of the system dynamics on the interfacial electronic structure. We then discuss how even minor changes in the chemical structure of the polymer backbone have been shown experimentally to change substantially the blend morphology and the resulting solar-cell efficiency. Taking a series of representative systems based on benzothiadiazole-quaterthiophene polymers and PC71BM, we elucidate the impact of the chemical changes on the ��local�� morphology. We focus on the extent of polymer-fullerene mixing, on their packing, and on the characteristics of the fullerene-fullerene connecting network in the mixed regions, which are all aspects that are difficult to access experimentally. We are able to rationalize the evolutions in power conversion efficiencies within the polymer series. Finally, we address the peculiarities observed in the PIPCP-fullerene blends. This work is supported by the Office of Naval Research, namely in the framework of the MURI Center on Advanced Organic Photovoltaics. Jean-Luc Br��das is a Belgian chemist and currently at Georgia Tech. He was a Distinguished Professor of Material Science and Engineering in the Physical Science and Engineering Division at KAUST, and at the Universit�� de Mons-Hainaut Belgium. He studied Chemistry (B.S. 1976) and obtained a PhD in 1979 at the Facult��s Universitaires Notre-Dame de la Paix (University of Namur), Belgium. His research deals with the structural, electronic, and optical properties of novel organic and nanomaterials with promising characteristics in the field of electronics, photonics, and information technology. Br��das is among the top 100 most cited chemists in the world, and is included in the list of the Highly Cited Researchers for Chemistry [2]. He is the Director of International Programs at the Center for Organic Photonics and Electronics at Georgia Tech. He is a member of the International Academy of Quantum Molecular Science (2011).[1] He is a Fellow of the American Association for the Advancement of Science, the American Chemical Society, the American Physical Society, and the Optical Society of America. 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

6 years

[Aspuru-Guzik Group List] ITAMP/HQOC Joint Quantum Sciences Seminar - Wednesday, April 18, 2018 @ 4:00

by Dakoulas, Samantha R

ITAMP/HQOC Joint Quantum Sciences Seminar Wednesday, April, 2018 4:00 PM, Jefferson 250 Prof. Harold Baranger, Duke University “Waveguide QED: Photon Correlations, Capture, and Production” Strong coupling between a local quantum system (qubit) and one-dimensional bosonic states has recently become experimentally feasible in a variety of plasmonic, photonic, circuit-QED, and cold-atom contexts. This has opened up a new field dubbed "waveguide QED". The key ingredient in the many new effects in this area is inelastic scattering into the one-dimensional continuum. Using such inelastic scattering as a unifying theme, I shall discuss our results on (i) characterization of photon correlations using the waiting-time distribution, (ii) capture of a photon into a bound state in the continuum, and (iii) photon production when the coupling is ultrastrong. In the ultrastrong example, we find surprisingly that the off-resonant inelastic emission is dominated by broadband photon production, coming from contributions in which the number of excitations is not conserved. Student Presentation by Yichao Yu will begin at 4:00 Guest Presentation will begin at 4:30 PM Refreshments will be provided. Samantha Dakoulas Faculty Assistant to Professors Lukin & Greiner & their groups Department of Physics 17 Oxford St., Lyman 324A Cambridge, MA 02138 P. (617) 496-2544

6 years

[Aspuru-Guzik Group List] Excitonics Seminar: April 17@4:30, RLE 36-428

by Catherine M Bourgeois

Please post and forward to your groups (Poster attached), thank you. Center for Excitonics presents: Polymer-Acceptor Bulk Heterojunction Solar Cells: From Chemical Structure to Packing and Efficiency April 17, 2018 at 4:30pm/36-428 Jean-Luc Bredas Department of Chemistry and Biochemistry, Georgia Tech [http://www.rle.mit.edu/excitonics/wp-content/uploads/2017/08/Jean-luc-Breda…] The morphology of the active layer of a bulk heterojunction (BHJ) solar cell, made of a blend of an electron-donating polymer and an electron-accepting fullerene or nonfullerene derivative, is known to play a determining role in device performance. Here, based on the results of molecular dynamics simulations and long-range corrected density functional theory calculations, we first describe the nature of the binding interactions at the donor�Cacceptor interfaces, the molecular-level packing in the pure phases as well as at these interfaces, and the impact of the system dynamics on the interfacial electronic structure. We then discuss how even minor changes in the chemical structure of the polymer backbone have been shown experimentally to change substantially the blend morphology and the resulting solar-cell efficiency. Taking a series of representative systems based on benzothiadiazole-quaterthiophene polymers and PC71BM, we elucidate the impact of the chemical changes on the ��local�� morphology. We focus on the extent of polymer-fullerene mixing, on their packing, and on the characteristics of the fullerene-fullerene connecting network in the mixed regions, which are all aspects that are difficult to access experimentally. We are able to rationalize the evolutions in power conversion efficiencies within the polymer series. Finally, we address the peculiarities observed in the PIPCP-fullerene blends. This work is supported by the Office of Naval Research, namely in the framework of the MURI Center on Advanced Organic Photovoltaics. Jean-Luc Br��das is a Belgian chemist and currently at Georgia Tech. He was a Distinguished Professor of Material Science and Engineering in the Physical Science and Engineering Division at KAUST, and at the Universit�� de Mons-Hainaut Belgium. He studied Chemistry (B.S. 1976) and obtained a PhD in 1979 at the Facult��s Universitaires Notre-Dame de la Paix (University of Namur), Belgium. His research deals with the structural, electronic, and optical properties of novel organic and nanomaterials with promising characteristics in the field of electronics, photonics, and information technology. Br��das is among the top 100 most cited chemists in the world, and is included in the list of the Highly Cited Researchers for Chemistry [2]. He is the Director of International Programs at the Center for Organic Photonics and Electronics at Georgia Tech. He is a member of the International Academy of Quantum Molecular Science (2011).[1] He is a Fellow of the American Association for the Advancement of Science, the American Chemical Society, the American Physical Society, and the Optical Society of America. 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

6 years

[Aspuru-Guzik Group List] [qip] Q ML reading group

by Ramis Movassagh

Dear all, We have our first organizational meeting today. If interested, feel free to show up. Space-time locations: CTP (near the group meeting room ) at 2 pm today. -- Ramis _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

6 years

[Aspuru-Guzik Group List] [qip] Fwd: [CMT Seminar] Special CMT seminar-Friday, April 13, 2018 @12:00pm noon

by Ramis Movassagh

space-time coordinates and the details of Oles' talk. The idea is that one can compute, with high accuracy, the spectral properties of disordered (containing some randomness) systems using free probability and random matrix theories. The Floquet systems will serve as a concrete example. Best, Ramis ---------- Forwarded message ---------- From: Lesley Keaney <lkeaney(a)mit.edu> Date: Fri, Apr 6, 2018 at 3:14 PM Subject: [CMT Seminar] Special CMT seminar-Friday, April 13, 2018 @12:00pm noon To: cmt_seminar <cmt_seminar(a)mit.edu>, chezpierre <chezpierre(a)mit.edu> Hello everyone, Please join us at *12:00pm* noon on *Friday, April 13, 2018 *for a *Special Condensed Matter* *Physics Seminar* with *Oles Shtanko, *Massachusetts Institute of Technology. The seminar will be held in the *Duboc room 4-331* Please see the details of Oles’ talk below. *Title:* Stability of Disordered Floquet Topological Phases *Abstract:* In modern experiments, high-frequency periodic fields are used to create Floquet topological phases of matter. Taking into account the complex nature of finite-frequency disorder contribution to the Floquet Hamiltonian, one may wonder about the stability of these systems against local disorder. We leverage modern free probability theory and ideas in random matrices to predict the fate of finite frequency Floquet topological phase in the presence of such disorder. We confirm, depending on disorder strength, the existence of gapped topological and gapless trivial phases, as well as a transition between them at a critical disorder strength. Our method can be applied to a variety of Floquet models and shows a good agreement with numerical simulations. arXiv: 1803.08519 <https://arxiv.org/abs/1803.08519> Date: Friday, April 13, 2018 Time: 12:00pm noon Room: Duboc room 4-331 Host: Brian Skinner Thank you, Lesley Lesley Keaney Administrative Assistant Condensed Matter Theory Group MIT Department of Physics Room 6C-339 Cambridge, MA 02139 617.253.4878 (phone); 617.253.2562 (fax) _______________________________________________ CMT_seminar mailing list CMT_seminar(a)mit.edu http://mailman.mit.edu/mailman/listinfo/cmt_seminar -- Ramis _______________________________________________ qip mailing list qip(a)mit.edu http://mailman.mit.edu/mailman/listinfo/qip

6 years

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aspuru-list April 2018