Noise-enabled high-efficiency cold atom nano-ratchets
Abstract
A cornerstone of the nanotechnological revolution of the twenty-first century is the human aspiration to build nanodevices that can match cellular machinery. However, for reasons that remain poorly understood, biological machines existing in nature significantly outperform artificially manufactured nano-devices, often by many orders of magnitude. This is true for all inorganic nano-devices no matter what the choice of architecture. Our current understanding of why biomolecular motors are so efficient despite being invariably swamped by surrounding incessant thermal Brownian fluctuations is that, counter-intuitively, they seem capable of harnessing energy from the random noise/fluctuations: As the noise increases the motor becomes more efficient. Cold atoms confined in dissipative optical lattices offer, by far, the most amenable architecture for elucidating the physical mechanisms by which biological machines convert random thermal fluctuations to useful work. The simplicity of atom-light interaction makes this architecture the most analytically accessible for optimizing device performance. Further, cold atom optical lattices offer experimenters unparalleled flexibility in tuning the coupling between the atomic ratchet and environmental fluctuations. The word "dissipative" refers to the use of near-resonant light: The confined atoms continually scatter spontaneous photons and undergo random recoils. These atomic recoils perfectly replicate Brownian fluctuations induced by thermal collisions in a biomolecular motor, making dissipative optical lattices especially suited for simulating bio-molecular motors. The goal of our experimental program is to broadly investigate cold atom transport in dissipative optical lattices for the purpose of implementing high-efficiency Brownian motors that can, for the first time ever, rival biomolecular motors in performance. Our specific objectives in this proposal are: 1. To implement highly efficient Brownian ratchets in dissipative optical lattices by making a first detailed study of ratchet-environment coupling in order to optimize ratchet performance. 2. To elucidate the specific physical mechanisms behind a Brownian ratchet s ability to sometimes perform significantly more efficiently when the environmental noise increases; this is the path toward creating an artificial nano device that can rival a biomolecular motor. The significance of the proposed research stems from the efficient performance of cellular machinery as a key motivation for developing viable nanotechnology - "if nature can do it, so can we". The scientific community s thrust toward building viable artificial nano-devices has relied on two principal approaches: First, there are biomimetic approaches to assembling robust nano-motors via self-assembly of biological components at the cellular level, which remain complicated. Second, there are inorganic "bottom-up fabrication" approaches which are simple and robust - here, the scientific community has focused on solid-state devices using lithographic / AFM (atomic force microscopy)/ STM (scanning tunneling microscopy) techniques. The challenge for both these rapidly growing fields, inorganic and biomimetic nano engineering, is to understand the bio-motor s intriguing ability to harness Brownian fluctuations in its environment. Dissipative optical lattices provide an ideal architecture to closely investigate the underlying mechanisms behind this phenomenon.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810431
Entities
People
- Samir Bali
Organizations
- Army Contracting Command
- Miami University
- United States Army