Van der Waals engineering for electrochemically tunable quantum materials
Abstract
Title: Van der Waals engineering for electrochemically tunable quantum materialsVan der Waals engineering for electrochemically tunable quantum materials Objective: Innovating electronic, information processing, and communication technologies will rely on our ability to understand and manipulate quantum electronic phenomena in materials. A promising solution to these problems lies at the interface of condensed matter physics and chemistry/electrochemistry. The isolation of the two-dimensional (2D) sheets that comprise layered, van der Waals (vdW) materials and their subsequent assembly with other atomically thinlayers of dissimilar materials permits the creation of new metastable 2D electronic structures that display emergent properties. Notably, as a direct consequence of this ~vdW heteroepitaxy~ method, artificial interlayer heterointerfaces are generated that can serve as the host lattice foratoms, ions or molecules inserted between the layers in an intercalation reaction. Electrochemical methods offer the greatest control over intercalation reactions since the reaction driving force can be precisely controlled to direct the formation of phases that may be inaccessible by other solid state synthetic routes, particularly metastable phases. Designing vdW heterointerfaces forelectrointercalation therefore provides a powerful new strategy to precisely engineer electronic materials and elicit novel physical properties. In cases where the fundamental electronic interactions are poorly understood, such as the pairing mechanisms in unconventional superconductors, the new phases accessed through this approach are expected to lead to new discoveries that shed light on this outstanding problem.Approach:The proposed research program has been designed to combine cross-disciplinary approaches and insights to discover and probe new quantum materials. Specifically, this program focuses on creating a unique subfamily of iron-based unconventional superconductors and exploring the newly created phase space.SOW:Specific tasks to be carried out in this program are:I. Isolation of atomically precise vdW heterostructures of FeCh (Ch= S, Se, Te). This foundational aim includes bulk crystal growth, exfoliation, thin-layer synthesis, as well as precise vdW heteroepitaxy to form heterostructures, including control over stacking angle/twist. These targets will be guided by input from theoretical collaborators.II. Investigation of unconventional superconductivity in dimensionally-controlled FeCh systems. In this objective, we will comprehensively elucidate the interplay betweendimensionality (number of layers) and intercalation-induced doping (both electron and hole doping) on the superconducting properties of FeCh layers for the first time.III. Tailoring unconventional SC with intercalated FeCh vdW heterostructures. Here, we will create a new family of these unconventional superconductors by preparing heterostructures of FeCh with dissimilar vdW material layers and intercalating the artificial heterointerfaces. The metastable vdW heterostructures prepared will permit us to access new electronic states that are inaccessible in bulk crystal measurements.IV. In situ resolution of intercalation structure/dynamics using advanced imaging probes.We will leverage established collaborations with researchers at national labs to evaluate the structural response of the 2D layers to vdW intercalation engineering. These studies will focus primarily on (scanning) transmission electron microscopy. Aim IV is a key aspect of this program since it emphasizes direct structural insight into new 2D systems.V. Option period (Year 3): Demonstration of regioselective intercalation in 2D twistronic layers. Here, we will engineer a periodic modulation in crystallographic registry (moir~pattern) between vdW bilayers of FeCh as a means of tunably nanostructuringintercalation sites. This concept will be applied to FeCh bilayers to give access to a new paradigm of superconducting s
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 23, 2019
- Source ID
- N000141912199
Entities
People
- Daniel Bediako
Organizations
- Office of Naval Research
- United States Navy
- University of California Regents