| quantum materials | |
|---|---|
| Name | Quantum materials |
| Type | Solid-state materials |
| Developers | Condensed matter physics community |
| First released | 20th century |
quantum materials
Quantum materials are classes of condensed matter in which quantum effects at the scale of electrons, spins, orbitals or topology produce emergent properties not explained by classical theories. They matter in Quantum Physics because their collective quantum states—such as superconductivity, topological order, and correlated electron behavior—both test fundamental theory and enable advanced technologies like quantum computing and quantum sensing.
Quantum materials denotes solids whose low-energy properties are dominated by quantum coherence, strong correlations, low-dimensionality, or topological structure rather than by independent-particle band pictures. The scope spans many families including high-Tc superconductors, topological insulators, quantum spin liquids, heavy-fermion compounds, and engineered heterostructures such as van der Waals heterostructures. Research integrates concepts from Condensed matter physics, Materials science, and Quantum information science and engages institutions like CERN-adjacent condensed-matter groups, national laboratories (e.g., Argonne National Laboratory, Lawrence Berkeley National Laboratory), and universities including MIT, Stanford University, and University of Cambridge.
Quantum materials are often classified by the dominant mechanism that gives rise to quantum behavior: - Strongly correlated electron systems: examples include cuprate superconductors (e.g., YBCO) and heavy fermion intermetallics such as CeCu6 and URu2Si2. - Topological materials: topological insulators like Bi2Se3 and topological semimetals such as Weyl and Dirac semimetal compounds (e.g., Na3Bi). - Low-dimensional materials: atomically thin crystals such as graphene, transition metal dichalcogenides (e.g., MoS2), and carbon nanotubes. - Quantum magnets and spin liquids: candidate materials include the Kitaev materials (e.g., α-RuCl3) and organic spin-liquid systems like κ-(BEDT-TTF)2Cu2(CN)3. - Engineered platforms: oxide interfaces (e.g., LaAlO3/SrTiO3), twisted bilayer graphene exhibiting moiré flat bands and correlated insulating/superconducting phases.
Key quantum principles underlying behavior are electron correlation, quantum entanglement, band topology and symmetry-protected states, and many-body coherence. Emergent phenomena include: - Superconductivity arising from Cooper pairing (conventional via BCS theory or unconventional pairing in cuprates and iron pnictides). - Fractionalization and anyonic excitations in fractional quantum Hall states and proposed non-Abelian quasiparticles relevant to topological quantum computing (see Majorana fermion proposals). - Topological surface or edge states protected by time-reversal or crystalline symmetries (as in Z2 topological insulators). - Heavy quasiparticles with enhanced effective mass in heavy-fermion materials, Kondo lattice behavior, and quantum critical points exemplified in materials studied by groups such as those led by Phil Anderson (conceptual influence) and experimentalists at Los Alamos National Laboratory. These phenomena connect to paradigms like the Hubbard model, Kondo effect, and symmetry-breaking described by Landau theory and beyond.
Characterization of quantum materials employs spectroscopy, scattering, and transport probes that directly access quantum degrees of freedom: - Angle-resolved photoemission spectroscopy (ARPES) for band structure and surface states (pioneered in groups at Stanford and Lawrence Berkeley National Laboratory). - Scanning tunneling microscopy/spectroscopy (STM/STS) for local density-of-states and quasiparticle interference. - Neutron scattering and muon spin rotation (μSR) for magnetic excitations and order; facilities include ISIS neutron source and Oak Ridge National Laboratory's Spallation Neutron Source. - Quantum transport measurements (Hall effect, magnetoresistance) and low-temperature techniques using dilution refrigerators at labs like RIKEN and national metrology institutes. - X-ray techniques such as resonant inelastic x-ray scattering (RIXS) and synchrotron-based angle-resolved probes at facilities like European Synchrotron Radiation Facility. Material synthesis and device fabrication use molecular beam epitaxy (MBE), chemical vapor deposition (CVD), and exfoliation for van der Waals materials.
Theoretical description combines model Hamiltonians and first-principles methods: - Model Hamiltonians: the Hubbard model, t-J model, Kitaev model, and Anderson models capture correlation and magnetism. - Many-body methods: dynamical mean-field theory (DMFT), density matrix renormalization group (DMRG), tensor network states, and quantum Monte Carlo address strong correlations. - First-principles: density functional theory (DFT) often augmented with +U or DMFT to include correlations; codes include VASP, Quantum ESPRESSO, and WIEN2k used by computational materials groups. - Emerging numerical platforms: machine learning accelerated materials discovery and quantum simulation on platforms provided by companies such as IBM and Google for variational quantum eigensolvers relevant to model Hamiltonians. Interplay between theory and experiment is essential for predicting topological invariants, phase diagrams, and response functions.
Quantum materials underpin technologies in quantum information, sensing, and energy: - Superconductors are central to superconducting qubits (used by IBM Quantum and Rigetti Computing) and to high-field magnets in MRI and particle accelerators. - Topological materials and Majorana platforms are pursued for fault-tolerant topological quantum computing by academic groups and startups. - Two-dimensional materials drive nanoelectronics, spintronics, and valleytronics devices, with industrial interest from semiconductor companies and consortia such as the Graphene Flagship. - Strongly correlated oxides enable memristive elements and neuromorphic architectures; oxide interfaces are promising for oxide electronics. Advances in quantum materials drive both fundamental tests of Quantum Physics and applied platforms for next-generation information and energy technologies.
Category:Condensed matter physics Category:Materials science