Neutron-interferometry for studying dynamical quantum-behaviour

In neutron interferometers, quantum interference effects of matter waves of massive particles are exhibited in macroscopic-scale setups; neutron interferometry has been utilized for more than four decades and is now established as an ideal tool for the investigations of fundamental features of quantum mechanics with matter-wave. By using this technique, lots of text-book experiments of quantum physics are carried out such as demonstrations of 4pi spinor symmetry of 1/2-spin, spin superposition, gravitationally induced phase and non-inertial motional effects. More recently, parallel with the development of quantum information technique, quantum features of entanglement between degrees of freedom in a single quantum particle, i.e., neutron, are studied intensively with the use of neutron interferometer setups. In this project, following our recent successful investigations of foundations of quantum mechanics with neutrons, we proceed with studies of fundamental dynamical behaviours of quantum particles. Six major research targets are proposed practically: - Studies of various forms of quantum Cheshire-cat effects emerging in neutron interferometer experiments - Implementation of simultaneous path weak-measurements in multi-path neutron interferometer - Studies of extended situation of quantum-box paradox - Studies of Leggett-Garg inequality describing quantum-causality of neutrons - Implementation of protective measurements with neutrons - Fundamental studies of incompatible dynamical properties of quantum particles In the previous project Weak values obtained in neutron optical experiments (September 2013 ~ August 2017), we accomplished experimental investigations of various aspects of weak-measurements and weak- values. On the basis of these achievements, we consider that studying fundamental features of dynamical behaviours of quantum particles in more detail is actually feasible. Recent notable developments of quantum information and communication technology have brought a new flavor of understanding fundamental perceptions of quantum mechanics. The use of matter-wave optical setups, in particular neutron interferometers, can open up new perspectives for the experimental accessibility of the fundamental quantum dynamics. We hope that our experiments will unveil new aspects of quantum dynamics on a fundamental level which are abundant in accessible information of a quantum system than those in classical physics. In all cases experimental investigation will have priority and theoretical support will be provided from collaborations with other groups in USA, France, Australia, Japan and worldwide. The aim of the project isto contributealso to the impressiveprogressof quantum optics andquantum information/communication technology by the use of the specific properties of neutrons as an elementary matter wave system.