Semiconductor Quantum Photonics: Control of Spin, Exciton and Photon Interactions by Nano-Photonic Design

我们寻求利用III-V半导体的高度优势特性来实现量子科学和固态材料技术的议程设定进展。我们在下一代量子效应（如叠加和纠缠）的制度下工作，其中III-V系统具有许多有利的属性，包括与光的强相互作用，皮秒控制时间，以及电子波函数被环境干扰之前的微秒相干时间。我们采用纳米光子设计的原则，以获得新的物理制度和潜在的长期应用。由于概念和制造技术的进步，许多这样的机会是在过去几年才出现的。概念上的进步包括实现量子发射器只在一个方向发射，如果精确地定位在光场中，可以通过特定的晶格设计实现无散射传播的波包，可以在一个光子的水平上实现非线性，并且可以实现量子封锁，其中一个粒子阻挡了另一个粒子的通过。现在正是利用这些概念进步的时候。我们将其与制造技术的进步相结合，这些技术允许实现例如可重构设备，并在芯片上控制电子和光子特性。我们利用高度发达的III-V制造技术，该技术是当今大多数固态光源的基础，以实现各种基于芯片的量子物理和设备演示。我们的主要目标包括单光子水平的可重构器件，基于精确定位在纳米光子结构中的量子点的完全受限状态的单光子逻辑门，以及通过设计光场来耦合状态，利用可重构能力来增强或抑制光学过程。量子点还具有有利的自旋（与电子相关的磁矩）特性。我们计划在片上几何图形中实现光子连接在一起的自旋，通往量子网络的路线，以及长期的量子计算机应用。与量子点一样，III-V量子阱与光强烈相互作用，形成称为极化子的新粒子。我们建议开辟拓扑极化电子学的新领域，在该领域中，晶格的纳米光子设计导致不受散射保护的状态，并产生人工磁场。这为模拟量子化霍尔效应的新的物质耦合状态开辟了道路，但在一个与电子具有根本不同波函数的系统中。最后，我们的计划还取决于优秀的晶体生长。我们的目标是限制量子点技术长期扩展的主要问题之一，即位点控制。我们将采用两种方法，其中包括图案，清洁和晶体生长的组合来精确定义量子点的位置，这两种方法都基于在预定位置形成坑的种子生长。这里的成功将是使半导体量子光学与大多数已建立的半导体技术（可扩展光刻工艺已成为其影响的决定性特征）所享有的地位保持一致的重要一步。

We seek to exploit the highly advantageous properties of III-V semiconductors to achieve agenda setting advances in the quantum science and technology of solid state materials. We work in the regime of next generation quantum effects such as superposition and entanglement, where III-V systems have many favourable attributes, including strong interaction with light, picosecond control times, and microsecond coherence times before the electron wavefunction is disturbed by the environment. We employ the principles of nano-photonic design to access new regimes of physics and potential long term applications. Many of these opportunities have only opened up in the last few years, due to conceptual and fabrication advances. The conceptual advances include the realisation that quantum emitters emit only in one direction if precisely positioned in an optical field, that wavepackets which propagate without scattering may be achieved by specific design of lattices, and that non-linearities are achievable at the level of one photon and that quantum blockade can be realised where one particle blocks the passage of a second. The time is now right to exploit these conceptual advances. We combine this with fabrication advances which allow for example reconfigurable devices to be realised, with on-chip control of electronic and photonic properties. We take advantage of the highly developed III-V fabrication technology, which underpins most present day solid-state light emitters, to achieve a variety of chip-based quantum physics and device demonstrations. Our headline goals include reconfigurable devices at the single photon level, a single photon logic gate based on the fully confined states in quantum dots positioned precisely in nano-photonic structures, and coupling of states by designed optical fields, taking advantage of the reconfigurable capability, to enhance or suppress optical processes. Quantum dots also have favourable spin (magnetic moments associated with electrons) properties. We plan to achieve spins connected together by photons in an on-chip geometry, a route towards a quantum network, and long term quantum computer applications. As well as quantum dots, III-V quantum wells interact strongly with light to form new particles termed polaritons. We propose to open the new field of topological polaritonics, where the nano-photonic design of lattices leads to states which are protected from scattering and where artificial magnetic fields are generated. This opens the way to new coupled states of matter which mimic the quantised Hall effects, but in a system with fundamentally different wavefunctions from electrons.Finally our programme also depends on excellent crystal growth. We target one of the main issues limiting long term scale up of quantum dot technologies, namely site control. We will employ two approaches, which involve a combination of patterning, cleaning and crystal growth to define precisely the quantum dot location, both based around the formation of pits to seed growth in predetermined locations. Success here will be a major step in bringing semiconductor quantum optics into line with the position enjoyed by the majority of established semiconductor technologies where scalable lithographic processes have been a defining feature of their impact.