Events at Physics |
Events on Friday, April 8th, 2022
- Theory Seminar (High Energy/Cosmology)
- Hot Qubits on the Horizon
- Time: 1:00 pm
- Place: Chamberlin 5280
- Speaker: Greg Kaplanek, McMaster University, Perimeter Institute
- Abstract: Perturbation theory for gravitating quantum systems tends to fail at very late times (a type of perturbative breakdown known as secular growth). We argue that gravity is best treated as a medium/environment in such situations, where reliable late-time predictions can be made using tools borrowed from quantum optics. To show how this works, we study the explicit example of a qubit hovering just outside the event horizon of a Schwarzschild black hole (coupled to a real scalar field) and reliably extract the late-time behaviour for the qubit state. At very late times, the so-called Unruh-DeWitt detector is shown to asymptote to a thermal state at the Hawking temperature.
- Host: George Wojcik
- Physics Department Colloquium
- Exploring the Heart of Quantum Matter with Extreme Magnetic Fields
- Time: 3:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Gregory Boebinger, NHMFL-FSU
- Abstract: In the wide range of materials that are grouped under the heading of “Quantum Matter”, intrinsic electronic charges and spins conspire in weird and collective ways to create new materials properties. Magnetic fields are a valuable tool for probing the mysteries that remain at the heart of Quantum Matter, where Nature creates 1/3 fractional electric charges, “spin liquids” of fixed charges but mobile spins, and high-temperature superconductivity in which the very existence of electrons as distinct particles becomes uncertain.
- Host: Alex Levchenko