Variable temperature measurement system for quantum devices from strongly correlated and topological materials

我们建议购买一个可变温度插入（VTI）用于量子电子器件的研究，在一个巨大的温度范围内，覆盖1.5K的深低温极限，一直到室温。 电子设备提供了一个强大的平台，从中可以研究新的量子力学效应，然后在许多情况下利用它们进行技术应用。 这种“量子设备”的一个例子是量子比特，量子计算机的构建块，它基于只能在最低可用温度下发现的长寿命量子态-绝对零度以上百分之几度。 自从15年前来到UBC以来，我的团队一直专注于需要超低温才能访问的量子设备类型，并建立了一个实验室，其中有几个稀释冰箱，用于实现这种条件。 然而，在过去的几年里，出现了一种新型的量子器件，其中通常基于石墨烯等2D材料的新材料在更高的温度下显示出量子效应。 这些效应通常基于组成电子之间的强相互作用或拓扑保护。 一个很好的例子是扭曲的双层石墨烯，其中两片石墨烯一个在另一个的上面，它们之间有一个精确的角度错位。 由此产生的莫尔图案产生了一种材料，可以从超导体到铁磁体再到相关绝缘体，只需在附近的栅极上施加几伏电压。 这为人们长期以来所希望的强相关材料开辟了可能性，这是加拿大的一个特殊专业领域，但现在是一个像计算机芯片中的晶体管一样可控的材料系统。 有趣的是，适用于量子比特和其他“传统”量子设备的超低温不仅不方便，甚至可能隐藏最有趣的现象，使VTI对于研究新一代设备至关重要。 我们将修改我们现有的测量系统之一，以适应拟议的VTI，利用我们实验室中已经存在的磁体低温恒温器（感谢先前的CFI资助）。 该系统将提供快速访问广泛的温度范围，非常适合2D材料，包括扭曲的双层石墨烯。 我们的团队已经成为加拿大量子电子器件测量领域的领导者;这笔资金将使我们能够迅速扩展到强相关和拓扑器件这一有前途的新领域。

We propose to purchase a Variable Temperature Insert (VTI) for the study of quantum electronic devices, over an enormous temperature range covering the deeply cryogenic limits of 1.5K, all the way up to room temperature. Electronic devices offer a powerful platform to from which to study novel quantum mechanical effects, then in many cases to harness them for technological applications. One example of such "quantum devices" are qubits, the building block of quantum computers, which are based on long-lived quantum states that can only be found at the lowest available temperatures--within a few hundredths of a degree above absolute zero. Since arriving at UBC 15 years ago my group has specialized in the type of quantum devices that require ultra-low temperatures to access, and have built up a lab with several dilution refrigerators optimized for achieving such conditions. In the last few years, however, a new type of quantum device has emerged in which new materials, often based on 2D materials such as graphene, show quantum effects at much higher temperatures. These effects are typically based on strong interactions between the constituent electrons, or on topological protection. A beautiful example is twisted bilayer graphene, in which two sheets of graphene are deposited one atop the other with a precise angle misalignment between them. The resulting Moire pattern yields a material that can be tuned from superconductor to ferromagnet to correlated insulator with just a few volts on a nearby gate. This opens up the possibilities that were long hoped-for with strongly correlated materials, an field of particular expertise in Canada, but now in a material system that is as controllable as the transistor in a computer chip. Interestingly, the ultra-low temperatures appropriate for qubits and other "conventional" quantum devices are not only inconvenient, but may even hide the most interesting phenomena from study, making a VTI critical for the study of this new generation of devices. We will modify one of our existing measurement systems to fit the proposed VTI, taking advantage of the magnet cryostat already in our lab (thanks to previous CFI funding). The system will offer the fast access to a broad temperature range ideally suited to 2D materials, including twisted bilayer graphene. Our group has already established itself as a leader in quantum electronic device measurements in Canada; this funding will enable us to rapidly expand into the promising new area of strongly correlated and topological devices.