Delayed choice qubit Lorentz rotations
APA
Dressel, J. (2016). Delayed choice qubit Lorentz rotations . Perimeter Institute. https://pirsa.org/16060099
MLA
Dressel, Justin. Delayed choice qubit Lorentz rotations . Perimeter Institute, Jun. 14, 2016, https://pirsa.org/16060099
BibTex
@misc{ pirsa_PIRSA:16060099, doi = {10.48660/16060099}, url = {https://pirsa.org/16060099}, author = {Dressel, Justin}, keywords = {Quantum Foundations}, language = {en}, title = {Delayed choice qubit Lorentz rotations }, publisher = {Perimeter Institute}, year = {2016}, month = {jun}, note = {PIRSA:16060099 see, \url{https://pirsa.org}} }
For a spin 1/2 (a qubit), Hamiltonian evolution is equivalent to an elliptic rotation of the (Bloch) spin vector in 3D space. In contrast, measurement alters the state norm, so may not be described as such a rotation. Nevertheless, extending the 3D spin vector to a 4D "spacetime" representation allows weak measurements to be interpreted as hyperbolic (boost) rotations. The combined Hamiltonian and measurement dynamics in continuous weak measurement trajectories are then equivalent to (stochastic) Lorentz transformations. Notably, in superconducting circuit QED implementations, the choice between which type of stochastic rotation occurs may be made long after the qubit and measurement field interact.