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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">Please join us for a special Colloquium today, at<b> 3:45 PM</b> in The Robert Smith Seminar Room. There will be a reception at
<b>3:30PM</b> in the Atrium. Details concerning the talk are as follows: <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">Speaker</span><span style="font-size:12.0pt;font-family:"Arial",sans-serif">: Diana Qiu (University of California - Berkeley)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">Date: Tuesday, January 22, 2019<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">Time:
<b>3:45PM</b><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">Place: 1080 Physics Research Building, The Robert Smith Seminar Room<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">Title: “Excitons in Flatland: Exploring and Manipulating Many-body Effects on the Opitcal Excitations in Quasi-2D Materials”</span><span style="font-family:"Arial",sans-serif"><o:p></o:p></span></p>
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<span style="font-size:12.0pt;font-family:"Arial",sans-serif">Abstract: Since the isolation of graphene in 2004, atomically-thin quasi-two-dimensional (quasi-2D) materials have proven to be an exciting platform for both applications in novel devices and exploring
fundamental phenomena arising in low dimensions. This interesting low-dimensional behavior is a consequence of the combined effects of quantum confinement and stronger electron-electron correlations due to reduced screening. In this talk, I will discuss how
the low-energy optical excitations (excitons) in quasi-2D materials, such as monolayer transition metal dichalcogenides and few-layer black phosphorus, differ from typical bulk materials. In particular, quasi-2D materials are host to a wide-variety of strongly-bound
excitons with unusual excitation spectra and massless dispersion. The presence of these excitons can greatly enhance both linear and nonlinear response compared to bulk materials, making them ideal candidates for optoelectronics and energy applications. Moreover,
due to enhanced correlations and environmental sensitivity, the electronic and optical properties of these materials can be easily tuned. I will discuss how substrate engineering, stacking of different layers, and the introduction or removal of defects can
be used to tune the band gaps and optical selection rules in quasi-2D materials.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial",sans-serif">The website for the colloquium is
<a href="https://physics.osu.edu/physics-colloquium-schedule"><span style="color:#0563C1">https://physics.osu.edu/physics-colloquium-schedule</span></a><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Segoe Script";color:blue">Robin<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#0070C0"><img border="0" width="224" height="45" style="width:2.3333in;height:.4687in" id="Picture_x0020_1" src="cid:image001.png@01D4B234.87C316A0" alt="The Ohio State University"><o:p></o:p></span></p>
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<b><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#BB0000;background:white">Robin Patterson</span></b><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#333333"><br>
Program Coordinator<br>
</span><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#BB0000;background:white">Department of Physics</span><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#333333">
<br>
1040K Physics Research Building, 191 W. Woodruff Avenue, Columbus, OH 43210<br>
(614) 292-8523 Office (614) 292-7557 Fax<br>
</span><u><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:blue;background:white"><a href="mailto:patterson.716@osu.edu">patterson.716@osu.edu</a></span></u><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#333333">
<a href="http://osu.edu/"><span style="color:blue;background:white">osu.edu</span></a>
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