Weak measurements by Alex Matzkin (Lecture - 01) скачать в хорошем качестве

Weak measurements by Alex Matzkin (Lecture - 01)

21 November 2016 to 10 December 2016 VENUE Ramanujan Lecture Hall, ICTS Bangalore Quantum Theory has passed all experimental tests, with impressive accuracy. It applies to light and matter from the smallest scales so far explored, up to the mesoscopic scale. It is also a necessary ingredient for understanding the evolution of the universe. It has given rise to an impressive number of new technologies. Yet it suffers from internal problems of consistency. On top of this, its unification with general relativity is still problematic, and no fully satisfactory quantum theory of gravity yet exists. This program will explore the current state of the art and future perspectives in the foundations of quantum theory, also in connection with its unification with general relativity. It consists of a two-week school, followed by a discussion meeting. The topics to be covered in the school include: School 1st Week - Theory: The measurement problem and its proposed solutions, Role of gravity in wave function collapse, Weak measurements, Quantum Measure and the Born rule, Trace Dynamics and Non-Markovian Dynamics. School 2nd Week - Experiment: Matter wave interferometry, optomechanics experiments, entanglement experiments, tests of decoherence and experimental tests of the quantum measure. A Discussion Meeting will be held during the 3rd week. During this meeting, the following questions will be addressed: What is the state of the art in experiments testing quantum theory with light, and with matter? What are the conceptual implications of gravity applied to quantum systems? What are the limitations imposed by, or new possibilities allowed by entanglement in relativistic quantum systems? How can we arrive at a coherent description of the early universe? Do we need a deeper level theory, which goes beyond quantum theory? More information about the program will be added in the near future. CONTACT US: fpqp@icts.res.in PROGRAM LINK: https://www.icts.res.in/program/fpqp2016 Table of Contents (powered by https://videoken.com) 0:00:00 ICTS 0:00:04 SPEAKERS: Markus Arndt Caslav Bruckner 0:00:11 Alex Matzkin 0:01:31 Abstract: What is the value of a given physical property of a quantum system at some intermediate time between the system preparation in an initial 0:03:13 Abstract: ... The answer to this question hinges on the peculiar status of quantum measurements. 0:05:23 Outline 0:09:09 1.1 State vectors and physical reality 0:10:51 Issue at stake: Why is science so successful 0:12:59 Example: Classical mechanics 0:14:38 The problem with quantum theory: 0:15:57 Present state: a supermarket of "interpretations" 0:21:10 Is the state vector more than a bookkeeping device 0:22:04 1.2 Observables and eigenstates 0:24:56 1.3 Counterfactuals and paradoxes 0:25:15 Delayed choice (Wheeler 1983) 0:27:01 Delayed choice (Wheeler 1983) "paradox": delay insertion of 2nd BS after the particle entered interferometer 0:28:08 Counterfactuals lead to paradoxes (Bohr...): 0:28:39 Three Box Paradox (Aharonov and Vaidman 1991) 0:29:34 Open a box : projectors 0:30:27 Where can we find the particle between t=t; and t=t 0:33:02 At some intermediate t, is the particle in box A 0:37:28 At some intermediate t, is the particle in box B 0:40:58 The "paradox": 0:43:46 2.1 Quantum measurements: Postulates 0:45:15 Quantum measurements postulates 0:45:58 Application: Qubit (spin I/2) 0:47:14 Measurement postulates: need of a more physical model 0:48:26 2.2 Classical measurements with pointers 0:50:25 Recalling the Poisson bracket 0:57:35 Classical measurements 0:58:30 Probability distributions for a dichotomic A(x,p) = 1 Configuration space distributions 0:59:46 Ideal measurement 1:00:43 2.3 Quantum pointers: Von Neumann model 1:06:44 Von Neumann model 1:11:27 Von Neumann model: dichotomic A 1:12:45 2.4 Non-ideal measurements 1:14:31 Quantum non-ideal measurements 1:15:37 2.5 Summary 1:17:53 Lectures on Weak Measurements 1:18:10 3.1 Strong measurements at intermediate times