Context
New moiré superconductor opens the door to new quantum materials
About Moiré Materials:
- Materials exhibiting unique properties due to an interference pattern formed when two repetitive structures are overlaid at a slight angle.
- Creation of Moiré Materials
- Formation: Created by stacking two layers of 2-D materials, like tungsten diselenide (tWSe₂), and twisting one layer at a small angle (e.g., 3.65º).
- Resulting Effect: The twist forms a moire pattern, which leads to new electronic behaviors not observed in individual layers.
- Electronic Properties
- Flat Bands: The twist in layers creates flat bands in the electronic structure, where electrons move slowly with nearly constant energy.
- Electron-Electron Interactions: Slow-moving electrons enhance electron-electron interactions, which are important for superconductivity.
- Research on Tungsten Diselenide (tWSe₂)
- Superconductivity: tWSe₂ (a semiconductor moiré material) exhibits superconductivity at a transition temperature of approximately –272.93º C.
- Comparison with High-Temperature Superconductors: The transition temperature of tWSe₂ is comparable to that of high-temperature superconductors.
- Stability: The superconducting state in tWSe₂ is more stable than in other moiré materials.
- Comparison with Graphene-Based Superconductors
- Graphene Superconductors: Achieve superconductivity through electron-lattice interactions and flat band formation.
- tWSe₂ Superconductivity: Achieved through electron-electron interactions, making it more stable and potentially more robust compared to graphene-based superconductors.
- Electron-Lattice Interactions: These interactions occur between electrons and the atomic lattice (the arrangement of atoms in a material’s crystal structure).
- Significance of Findings
- Practical Applications: Stable superconductivity at low temperatures can enable advancements in quantum computing and electronics.
- Future Technologies: Findings can aid in designing new materials for future technological innovations.
Superconductivity Overview
- Definition: Superconductivity refers to the property of certain materials that allow them to conduct direct current (DC) electricity without energy loss when cooled below a critical temperature (Tc).
- Magnetic Field Expulsion: Superconducting materials also expel magnetic fields when transitioning to the superconducting state.
- MRI Machines: Use an alloy of niobium and titanium as a superconducting material for generating high magnetic fields.
Source: TH
Previous Year Question
Which one of the following is the context in which the term “qubit” is mentioned?
[UPSC Civil Services Exam – 2022 Prelims]
(a) Cloud Services
(b) Quantum Computing
(c) Visible Light Communication Technologies
(d) Wireless Communication Technologies
Answer: (b)