BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:Demonstration of Quantum Error Correction using Schrödinger Cat S tates DTSTART:20171002T161500 DTEND:20171002T171500 DTSTAMP:20260407T051301Z UID:f74b300635f8bf5d8d1f9eea1b74b2d0a61eb535f4271b9e8197ba1d CATEGORIES:Conferences - Seminars DESCRIPTION:Prof. Steven M. Girvin\, Yale university\nBio: Steven Girvin i s a theoretical physicist who studies the quantum mechanics of large colle ctions of atoms\, molecules and electrons such as are found in superconduc tors\, magnets and transistors. Of particular current interest to him is t he engineering question of whether it is possible to build a quantum compu ter. He is collaborating with experimentalists Rob Schoelkopf and Michel D evoret in Applied Physics who are constructing superconducting circuit ele ments which might someday form the basis for a quantum computer. Such a co mputer could in principle solve problems which are impossible on ordinary computers. However in order to build a quantum computer it is necessary to create circuit devices which behave quantum mechanically (like individual atoms) despite the fact that they are macroscopic and consist of a very l arge number of atoms. In addition to potential practical applications\, th is difficult challenge will help us better understand the connections betw een the microscopic quantum world and the macroscopic classical world of e veryday experience.\n\nProfessor Girvin is interested in quantum many-body physics\, and quantum and classical phase transitions\, particularly in d isordered systems. A quantum phase transition is one which occurs at zero temperature as some parameter in the Hamiltonian is varied. Using path int egral techniques\, one can often show that a quantum critical point in a d -dimensional system is in the same universality class as some other classi cal system in (d+1)-dimensions. He is interested in finding quantities tha t are universal properties of the system near the critical point and are i ndependent of all microscopic details. For example\, the electrical conduc tivity of some two-dimensional conductors at critical points is a universa l dimensionless number of order unity times the quantum of conductance\, e 2/h.\n\nMuch of his work has been on the quantum Hall effect\, but he has also worked on the superconductor-insulator transition\, the vortex glass transition in high Tc superconductors\, superfluid helium in fractal aerog el\, the Anderson localization problem\, the Coulomb blockade problem in m esoscopic device physics\, and on quantum spin chains.\n\nHis work is appr oximately evenly divided between analytical theories and numerical simulat ions.\nA revolution is underway in the construction of ‘artificial atoms ’ out of superconducting electrical circuits.  These macroscopic ‘ato ms’ have quantized energy levels and can emit and absorb quanta of light (in this case microwave photons)\, just like ordinary atoms. The large si ze of these ‘atoms’ yields remarkably strong atom-photon coupling and has given us the ability to completely control and measure the quantum sta te of the electromagnetic field in a cavity at the level of individual mic rowave photons.\n \nIn particular\, it is now possible to create record l arge ‘Schrödinger cat’ photon states.   In addition to being used t o study quantum mechanics at macroscopic scales\, these cat states form a novel basis for quantum information processing in a ‘photonic’ quantum computer.  Recent experiments at Yale have successfully demonstrated qua ntum error correction that reaches the break-even point for the first time . This talk will present an elementary introduction to the field as well a s an overview of recent experimental progress.\n  LOCATION:Auditoire CE2 https://plan.epfl.ch/theme/generalite_thm_plan_publ ic?request_locale=fr&room=ce12&domain=places&dim_floor=1&lang=fr&dim_lang= fr&baselayer_ref=grp_backgrounds&tree_groups=centres_nevralgiques%2Cacces% 2 STATUS:CONFIRMED END:VEVENT END:VCALENDAR