Quantum interference in single-molecule devices

量子干涉为分子器件的开发提供了丰富的资源。如果能量在分子中有多种传输途径，或者电传输受分子内共振的影响，那么这些效应可以用于实际技术。例如，有可能制造出比目前的硅CMOS功耗低得多的晶体管，也有可能开发出改进的热伏打材料，以清除原本会被浪费掉的热量。理解这些现象也可能有助于揭示生物学中量子相干过程的假设，从光合作用到鸟类导航。该项目需要碳基装置的纳米制造，可以将单个分子插入其中。通过分子的电流将被测量，以期发现量子干涉的机制。一个主要的挑战将是设计和制造具有额外门的几何形状来控制量子干涉。该项目将涉及纳米制造，分子的化学附着，以及在一定温度和频率范围内的电子测量，特别是关于发现量子相干性的条件。一个成功的结果将是找到量子相干性增强器件性能的机制。该项目的目标是：-设计和合成具有特定量子干涉特性的分子结构，以便我们生成模块化设计功能目录，例如，锚基团和fano活性核心。-开发一个可重复接触和测量大范围分子的平台，以便可以定量分析不同的分子设计。-实施系统的测量策略，为分子设计决策提供信息，并研究单个分子的基本传输特性。-提供一个理论框架来分析实验结果，并发展支持愿景的基础。国家和国际报告强调了该项目所解决的挑战。DSTL 2014年的分析，英国量子技术景观，观察到（第55页），“最近的研究已经证明了组装的可能性，在分子水平上，高效设备将能够从废热中提供电力. ...英国在实验能力方面存在差距，这将需要多学科合作。”ITRS（国际半导体技术路线图）呼吁对“分子电子学知识库”进行“进一步的基础工作”。这项关于新型分子逻辑系统的工作将直接解决“非cmos器件技术”研究领域的问题，EPSRC的战略是根据英国强大的制造业基础和在新型纳米或微电子领域取得领先地位的潜力，保持投资。石墨烯在逻辑和电子器件中的新用途将有助于EPSRC的“石墨烯和碳纳米技术”研究领域。该项目还将在更高的层面上为EPSRC的“新量子技术的量子物理学”（利用量子现象减少消耗和处理信息的电子纳米器件）和“功能材料的纳米级设计”（用于制造分子纳米电子器件的新合成工具，可以廉价和大量生产）的重大挑战做出贡献。该项目与EPSRC计划资助“电子纳米器件中的量子效应”保持一致，并与化学系（牛津大学）的Harry Anderson教授和兰开斯特大学的Colin Lambert教授合作。主题是：物理科学、量子技术

Quantum interference offers a rich resource which could be exploited in molecular devices. If there are multiple pathways for energy transport through a molecule, or if electrical transport is subject to resonances within a molecule, then these effects could be exploited for practical technologies. For example, it may be possible to make transistors with much lower power consumption than current silicon CMOS, and it may be possible to develop improvement of thermovoltaic materials for scavenging heat that would otherwise be wasted. Understanding such phenomena may also shed light on postulated quantum coherent processes in biology, ranging from photosynthesis to bird navigation.The project requires nanofabrication of carbon-based devices into which individual molecules can be inserted. The current through the molecules will be measured with a view to discovering mechanisms of quantum interference. A major challenge will be to devise and fabricate geometries with additional gates to control the quantum interference. The project will involve nanofabrication, chemical attachment of the molecules, and electrical measurements over a range of temperatures and frequencies, with especial regard to discovering the conditions under which quantum coherence can be found. A successful outcome will be to find regimes in which quantum coherence gives enhanced device performance.The objectives of the project are:- Design and synthesise molecular structures that are engineered to have specific quantum interference properties, so that we generate a catalogue of modular design features including, for example, anchor groups and Fano-active cores. - Develop a platform for reproducibly contacting and measuring a wide range of molecules, so that different molecular designs can be analysed in a quantitative matter. - Implement a systematic measurement strategy to inform molecular design decisions and to investigate fundamental transport properties of individual molecules. - Provide a theoretical framework to analyse experimental results and to develop the foundation underpinning the vision. National and international reports highlight challenges addressed by this project. DSTL's 2014 analysis, UK Quantum Technology Landscape, observes (p. 55) that 'Recent research has demonstrated the possibility of assembling, at the molecular level, highly efficient devices that will be able to deliver electrical power from waste heat. ... There is a UK gap in experimental capability, which will need multi-discipline collaboration'. ITRS (the International Technology Roadmap for Semi- conductors) calls for 'further fundamental work' on the 'knowledge base for molecular electronics'. This work on novel molecular logic systems will directly address the 'Non-CMOS device technology' research area, where EPSRC's strategy is to maintain investment in light of a strong UK manufacturing base and the potential to secure a leading position on novel nano- or micro-electronics. Novel uses of graphene for logic and electronic devices will contribute to EPSRC's 'Graphene and carbon nanotechnology' research area. The project will also contribute, at a higher level, to EPSRC Grand Challenges in 'Quantum Physics for New Quantum Technologies' (electronic nanodevices that use quantum phenomena to decrease consumption and process information) and 'Nanoscale Design of Functional Materials' (new synthetic tools for the creation of molecular nanoelectronic devices which can be produced cheaply and in large quantities). This project is aligned with the EPSRC Programme Grant 'Quantum Effects in Electrinic Nanodevices' and is in collaboration with Prof Harry Anderson at the Department of Chemistry (Oxford) and Prof Colin Lambert (Lancaster).The Themes are:Physical sciencesQuantum technologies