Quantum/Classical Boundaries in Matter-Wave Solitons

点击翻译按钮获取中文摘要

General audience abstract: Physicists have found that quantum mechanics works perfectly to describe the micro-world of single or small numbers of electrons, protons, or atoms. Quantum correlations in these small systems, known as “quantum entanglement,” are the primary attribute driving the quest to realize quantum computation. For a quantum computer to exhibit an advantage over an ordinary classical computer, however, the number of entangled particles must be large, thus presenting obstacles, both technical and fundamental, to their implementation. NSF-funded graduate student researchers will perform experiments that explore the limits of quantum entanglement in the largest systems to date using self-stabilizing wavepackets of atoms, known as solitons. Although large for a quantum system, containing as many as 10,000 atoms, solitons confined to a one-dimensional line are bestowed with a special robustness that makes them ideal for exploring how far quantum physics may be extended into the macro-world. These experiments will help us understand the quantum/classical boundary, and how it may be extended to even larger systems. By performing these experiments, graduate students, several from underrepresented groups, learn the methods of experimental atomic physics in a state-of-the-art laboratory, gaining expertise that will follow them in their careers in academia, government, or industry. Technical audience abstract:Solitons are dispersion-less excitations that arise in nonlinear systems. They are found both in classical and quantum wave phenomena, such as waves propagating in water, plasmas, optical fibers, and in matter waves to name just a few examples. Solitons are one of the few non-trivial systems that are described by an exactly integrable model. The researchers will continue their experimental investigation of bright matter-wave solitons produced from Bose-Einstein condensates with attractive interactions, and specifically, they will explore the role of integrability in determining the quantum/classical boundary. Recent theory predicts that integrability will protect a macro/mesoscopic object from decoherence, and can lead to the observation of effects that are manifestly quantum in objects expected to be best described by mean-field theories. By harnessing integrability, the effects of quantum fluctuations and quantum entanglement may be extended to systems with a large number of degrees of freedom, and which are large in physical size. The research team has two specific goals: 1) to observe the integrability-breaking effect of quantum fluctuations on the binding of a higher-order soliton breather and 2) to study the fast and slow collision regimes of a fundamental soliton interacting with a repulsive barrier made from a light sheet, and to exploit this geometry to realize a matter-wave soliton interferometer.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.