# Online: Seminar, Matthias Christandl (University of Copenhagen), Fault-Tolerant Coding for Quantum Communication #### calendar\_today Date and Time **January 26, 2021** 10:00AM - 10:00AM EST #### pin\_drop Location **Zoom** ![Christiandl](/sites/g/files/omnuum6611/files/styles/hwp_1_1__960x960_scale/public/mathpicture/files/christandl.png?itok=lLQWk1LH) **Location:** Zoom **Time:** Tuesday, January 26, 2021, 10:00 AM (Eastern US), 15:00 (UK/Eire), 16:00 (Central Europe), 23:00 (China) **Title:** Fault-Tolerant Coding for Quantum Communication **Abstract:** Designing encoding and decoding circuits to reliably send messages over many uses of a noisy channel is a central problem in communication theory. When studying the optimal transmission rates achievable with asymptotically vanishing error it is usually assumed that these circuits can be implemented using noise-free gates. While this assumption is satisfied for classical machines in many scenarios, it is not expected to be satisfied in the near term future for quantum machines where decoherence leads to faults in the quantum gates. As a result, fundamental questions regarding the practical relevance of quantum channel coding remain open. By combining techniques from fault-tolerant quantum computation with techniques from quantum communication, we initiate the study of these questions. As our main result, we prove threshold theorems for quantum communication, i.e. we show that coding near the (standard noiseless) classical or quantum capacity is possible when the gate error is below a threshold. (Joint work with Alexander Müller-Hermes, [https://arxiv.org/abs/2009.07161](https://urldefense.proofpoint.com/v2/url?u=https-3A__arxiv.org_abs_2009.07161&d=DwMGaQ&c=WO-RGvefibhHBZq3fL85hQ&r=nlqvXX6Jmbu52yOuosGBtKKs0OQ7eTClhH721mPk7Mc&m=JQLWf-h69iDMiGLYI78CR17IE7y24yZPwKfrTIBAOfo&s=OdQhNWKeFgJTA5r-Hw2pXT28UzUi7vrEK_NRzIZsg_A&e=)) **Additional Ways to Join** Join by telephone (use any number to dial in) +1 929 436 2866 +1 312 626 6799 +1 669 900 6833 400 669 9381 China Toll-free International numbers available: [https://harvar](https://harvard.zoom.us/u/aclg6kOggb)[d.zoom.us/u/aclg6kOggb](https://harvard.zoom.us/u/aclg6kOggb) One tap mobile: +19294362866,,779283357# US (New York) Join by SIP conference room system Meeting ID: 779 283 357 <779283357@zoomcrc.com> **Attachments** --- Attachments- [ picture\_as\_pdf Flyer.pdf ](/sites/g/files/omnuum6611/files/mathpicture/files/christandl_seminar_jan_26_2021.pdf) --- Share on:- [ Facebook ](#) - [ Twitter ](#) - [ Linkedin ](#) Save: [ Add to calendar calendar\_today ](https://mathpicture.fas.harvard.edu/node/1563866/event-feed.ics) Copy link link