Spin Squeezing and Entanglement in Bose-Einstein Condensates

点击翻译按钮获取中文摘要

This research will advance the state of the art in quantum-enhanced metrology, in which measurements of technically important quantities such as time and frequency, electro-magnetic fields and inertial forces are made with sensitivities approaching the limits set by fundamental quantum theory. Technological off-shoots of this research could lead to precision sensors for navigation and magnetometry, atomic clocks and emerging quantum technologies, including quantum computing, quantum simulation and quantum communication. The primary activity of the research is experimental investigation of ultracold atoms cooled to near absolute zero temperature where they form a uniquely quantum coherent state of matter known as a Bose-Einstein condensate. The experiments are performed by graduate students and undergraduate students who gain important expertise in the advanced laboratory techniques and quantum science. Additionally, the research is disseminated to a broad audience by incorporating results into classroom lectures, maintaining a dynamic website, hosting laboratory tours, making visits to local schools and facilitating popular press releases about the work. Specifically, this research project will investigate quantum squeezed and entangled states in atomic Bose-Einstein condensates with internal spin degrees of freedom. The investigations employ rubidium atomic Bose-Einstein condensates (BEC) confined in optical traps. The dynamic evolution of the internal spin degrees of freedom of the ensemble of atoms results from spin-dependent collisional interactions that generate quantum correlated or entangled states of the spin ensembles. This quantum system is simple enough so that both the ground state and evolution of non-equilibrium excited states can be quantitatively compared to theoretical predictions. Yet it offers a rich array of phenomena including spontaneous symmetry-breaking, entangled states and non-trivial geometric phases. The experimental platform provides a powerful combination of tools to explore important topics including quantum critical phenomena and the generation of massively entangled states. A common theme of the research is the role of finite size effects that are manifested in the quantum fluctuations of the system, and these studies will provide insight into fundamental principles of many-particle quantum mechanics that are important to many areas of physics. This work will build upon recent investigations of quantum spin dynamics that include the measurement of spin-nematic squeezing, demonstration of dynamical stabilization and parametric excitation, high precision studies of a second order quantum phase transition, and exploration of Kibble-Zurek universality in excitations across a quantum critical point.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.