Diamond scanning probe for characterization of topological insulators
Abstract
Strict low-weight requirements and large thermal loads characterizing the hypersonic flight result in skin-panels with reduced stiffness, thus prone to deformations and structure insta- bility. In this scenario, an optimal distribution of thermal protection systems (TPS) and an appropriate choice of skin-panel support can significantly reduce the structural weight, thus maximizing payload while ensuring aircraft survivability. A typical approach employed by single-stage-to-orbit (SSTO) spaceplanes such as Skylon and HOTOL, consists in separating thermal-shield material from load-bearing structure. In this case, the floating skin-panels only absorb the thermal loads while transmitting the aerodynamic loads to the underlaying ultra-light composite structure through a number of posts. The presence of thermal loads certainly makes hypersonics the harshest regime under an aerothermoelastic point of view; However, it is not clear if a structural design optimized for hypersonic speeds will still present satisfactory performance in the transonic regime, where flutter margins are typically at a minimum and numerical simulations often fail in predicting flutter during the flight tests. The experiments will be conducted in the NCKU Transonic Wind Tunnel facility, capable of providing a freestream Mach number between 0.8 and 1.2. The basic set-up will consist of an aeroelastically scaled panel hinged at the corners by four posts. Successive tests will employ a series of panels supported in the same fashion in order to assess the level of constructive and destructive interactions among panels undergoing flutter. Mass distribution will be altered by the addition of lumped loads to model the presence of thermal insulation layers. The simulation of the experiment will improve the fidelity of existing low-fidelity models and numerical simulations. As a new state of matter, Topological Insulators (TI) with insulating bulk but conducting surface states are recognized as the key for the implementation of low power consumption devices for high�performance and low power electronics, and quantum computing. To identify the full potential of TI materials, characterization and modelling of TI are needed. In this project, we will develop a full optical method to characterize TI. Our approach takes advantage of scanning quantum probe type technology. Because of the unique electromagnetic boundary conditions of Tl that relate the electric and magnetic fields at the surface of the TI, we monitor the change in far�field fluorescence from a single dipole as a function of the type of material: conductor vs insulator vs TI. The interference is due to interactions between the dipole and the effective mirror dipole inside and outside the material. We propose to use diamond pillars or nanodiamonds with single color centers, initially concentrating on the nitrogen�vacancy (NV) color center, to develop a robust scanning optical tool to characterize and identify TI. This technique has the potential of being fast and able to scan wide areas (typically hundreds of microns) with spatial resolution around the tens to hundred nanometer level. Another useful readout information of our method to characterize TI will use the magnetic sensing capability of NV centers to characterize the magnetic field response of TI to electric fields, since a magnetic field arises when an electric field is applied near the surface due to the special electromagnetic boundary properties of Tl. Our proposed method, based on novel electromagnetic modelling and scanning diamond probe technology, promises new insights into the characterization and optimization of materials for TI�based devices
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2023
- Source ID
- FA23862114125
Entities
People
- Brant C Gibson
Organizations
- Air Force Office of Scientific Research
- RMIT University
- United States Air Force