Observing indistinguishability of mutually separated particles
Hartmut Häffner, UC Berkeley
The quantum statistics theorem states that the wavefunction of two indistinguishable particles must be symmetrized. As a result, the phase acquired upon exchanging the particles is restricted to either 0 or π. Although this theorem has profound implications for the structure of nature—most notably for the stability of atoms and nuclei—its consequences are typically observed only indirectly, for example through the Pauli exclusion principle. Moreover, the bosonic or fermionic character of indistinguishable particles usually becomes relevant only at atomic scales or when their wavefunctions significantly overlap.
In contrast, ions confined in an ion trap are always separated by several micrometers due to their mutual Coulomb repulsion. This macroscopic separation naturally invites the interpretation of the ions as distinguishable particles. In this context, I will discuss the conditions under which the wavefunction of two trapped ions must nevertheless be symmetrized. Specifically, I discuss experiments that directly reveal a well-defined exchange phase by interfering a two-ion string with itself after a π rotation.
About the speaker
Hartmut Häffner is a Professor of Physics at UC Berkeley. He earned his PhD in 2000 from the University of Mainz in precision metrology, followed by a postdoc at NIST Gaithersburg focusing on Bose-Einstein condensates and dynamical tunneling. In 2001, he joined University of Innsbruck to implement quantum algorithms and explore trapped-ion quantum computers, where he realized a universal set of quantum gates, ion-state teleportation, and tomography of an eight-particle entangled state.
Since 2009, Haeffner leads is own group at UC Berkeley group developing novel quantum computing technologies. His team applies their quantum information expertise to precision measurements and tests of fundamental symmetries, including searching for Lorentz symmetry breaking and bounding the non-linearity of quantum mechanics. Recent achievements include pioneering 3D-printed ion traps for quantum computing, the observation of quantum synchronization, the coherent transfer of orbital angular momentum to a quantum rotor, and verifying the symmetrization postulate of quantum field theory using a rotational interferometer.
Location
QNC 0101
Light refreshments will be provided.
Add event to calendar
