Physics Department Colloquium

Date: Thu. 14 Sep, 2017 4:00 pm - 5:00 pm
Duration: 1 Hour
Location: Workman Center

Dr. Paul Arendt of the Physics Department will present the weekly colloquium. His talk is "Moving Qubits Around in Complex Time." What would it mean to be moving in both real and imaginary time? It turns out that we can actually devise a sensible way to do so, at least for the case of a quantum mechanical two-state system, known as a “qubit.” Perhaps more surprisingly, it also turns out to be a useful way to describe actual important physical processes which are done to qubits – measuring their properties. And when the qubits are in “entangled” states with other qubits, as is often the case when quantum mechanics fundamentals are being probed (by Alice and Bob), complex time propagation is still an efficient way to describe the qubit’s behavior. This talk will first introduce what a qubit is, and describe all of the different possible states in can be in. Then a paradox involving measurement of entangled states, using a model due to Zurek, will be presented – along with its resolution, which provides a lesson on what one cannot do with entangled states, and on how we really don’t need an “observer” to “collapse” a wave function. 4 p.m. in Workman 101