Weak values obtained in matter-wave interferometry

作者:Sponar Stephan*; Denkmayr Tobias; Geppert Hermann; Lemmel Hartmut; Matzkin Alexandre; Tollaksen Jeff; Hasegawa Yuji
来源:Physical Review A, 2015, 92(6): 062121.
DOI:10.1103/PhysRevA.92.062121

摘要

Weak values, introduced more than 25 years ago, underwent a metamorphosis from a theoretical curiosity to a powerful resource in photonics for exploring foundations of quantum mechanics, as well as a practical laboratory tool. Due to the tiny coherence volume of particles used in matter-wave optics, a straightforward implementation of weak measurements is not feasible. We have overcome this hurdle by developing a method to weakly measure a massive particle's spin component. A neutron optical approach is realized by utilizing neutron interferometry, where the neutron's spin is coupled weakly to its spatial degree of freedom. Here, we present how one can fully characterize the weak value of the Pauli spin operator (sigma) over cap (z) of neutrons by extracting its real and imaginary components, as well as its modulus. The results show good agreement with theoretical predictions and demonstrate that the (spin) weak value is actually accessible for a purely quantum system of massive particles.

  • 出版日期2015-12-14