Designing Functional Quantum Materials: From Anyons to Magnetic Storage

自石器时代以来，我们的社会和工业革命一直与新材料的发展密切相关，例如，硅晶体管的诞生使现代信息技术成为可能。然而，目前计算的局限性要求量子技术需要新的材料。固态材料是由按周期排列的数十亿个原子组成的。这种固体收集了来自原子的电子，每个电子都有一个电荷和一个自旋。虽然人们了解原子中很少的电子的行为，但它们在微米级固体中的基本物理属性在很大程度上隐藏在它们的电子和磁性之下。尽管材料的组成没有变化，但它们可能会变成金属、绝缘或超导，这就提出了一个关键的问题，即什么因素决定了这些不同的物质状态。为了刻画不同的状态，使用了破缺对称性的概念。在某些条件下，某些固体会变成铁磁体，自旋朝向特定的方向。由于选择了一个方向而不是所有其他可能的方向，因此称为对称破缺。最近，对量子物质的认识在我们的理解上经历了一系列激进和意想不到的革命。通过波函数的拓扑特征来区分不同的态。拓扑是指不受平滑变形影响的特性。例如，有孔的甜甜圈在拓扑上与有把手的咖啡杯相同，而没有孔的球在拓扑上与两者截然不同。将这一概念应用到物理学中，拓扑材料对杂质和缺陷具有免疫力，这是能量损失的来源。由于它们的导电能力，这些材料在量子技术的发展中具有巨大的潜力。在过去几十年中发展起来的另一个概念是纠缠，它表示没有描述量子态的局域量。在具有纠缠的拓扑阶段，存在着数学模型，其中出现了名为任意子的新类型的粒子，这种粒子对纠错量子计算机至关重要。我们的研究目标是为不同的目的设计功能材料，从用于量子计算机的任意子到用于磁存储的室温铁磁体。PI是发展微观理论的领先专家，这些理论弥合了数学模型和固态材料之间的差距。我们将与材料合成领域的其他专家合作，产生创造性和协同性的研究成果。我们的发现将引导我们发现未来的材料，这些材料将满足当前的社会需求，为量子技术奠定基础，并扩大我们目前理解的边界。这项研究将涉及在对加拿大社会和工业需求较高的领域培训下一代加拿大科学家。

Since the Stone Age, our social and industrial revolutions have been intimately tied to the development of new materials, an example being how modern information technology was made possible by the genesis of silicon transistors. However, current limitations on computing call for new materials needed for quantum technology. Solid-state materials are made of billions of atoms arranged in a periodic pattern. Such solids have collections of electrons donated from atoms, where each electron has an electric charge and a spin. While behaviours of few electrons in atoms are understood, their fundamental physical attributes inside micrometer-size solids are largely hidden under their electronic and magnetic properties. Materials may become metallic, insulating, or superconducting despite no change in their constituents, raising the critical question of what factors determine these different states of matter. To characterize different states, the concept of a broken symmetry has been used. Under certain conditions, some solids can become ferromagnets where the spins align toward a particular direction. Since one direction is chosen over all other possible directions, it is referred to as broken symmetry. Recently, knowledge of quantum matter has advanced through a series of radical and unexpected revolutions in our understanding. Distinct states are differentiated by the topological character of their wave functions. Topology refers to a property that is immune to smooth deformations. For example, a donut with a hole is topologically identical to a coffee mug with a handle, while a ball without a hole is topologically distinct from both. Applying this concept to physics, topological materials have an immunity to impurities and defects, sources of energy loss. Due to their ability to conduct electrical current, these materials have great potential in the development of quantum technology. Another notion evolved over the last few decades is entanglement, which denotes the absence of local quantities describing the quantum state. In topological phases with entanglement, there exist mathematical models where new types of particles named anyons, essential for error-correcting quantum computers, emerge. Our research goal is designing functional materials for distinct purposes ranging from anyons for quantum computers to room temperature ferromagnets for magnetic storage. The PI is a leading expert in developing microscopic theories that bridge a gap between mathematical models and solid-state materials. We will collaborate with other experts in the materials synthesis to generate creative and synergetic research outcomes. Our findings will guide us to discover future materials that will address current societal needs, lay the foundations for quantum technology, and expand the boundaries of our current understanding. This research will involve training the next generation of Canadian scientists in areas of high demand for Canadian society and industry.