| condensed matter physics | |
|---|---|
| Name | Condensed matter physics |
| Field | Physics |
| Subdiscipline | Solid-state physics, soft matter |
| Institutions | Bell Labs, CERN (materials programs), IBM Research, MIT, Stanford University, University of Cambridge |
| Notable people | Philip W. Anderson, John Bardeen, Lev Landau, Pieter W. Anderson |
| Related | Quantum mechanics, Statistical mechanics, Materials science |
condensed matter physics
Condensed matter physics is the branch of physics that studies the macroscopic and microscopic properties of matter in condensed phases, principally solids and liquids, using concepts from Quantum mechanics and Statistical mechanics. It matters in the context of Quantum Physics because emergent phenomena such as superconductivity, magnetism, and topological order arise from collective quantum behavior of large numbers of particles and underpin modern technologies in electronics, photonics, and quantum information.
Condensed matter physics encompasses theoretical, experimental, and computational study of phases of matter, phase transitions, and collective excitations in systems with many degrees of freedom. Historically rooted in solid-state physics, the field bridges fundamental quantum theory and practical Materials science through institutions such as Bell Labs and university research groups at MIT and Stanford University. Key concepts include quasiparticles, symmetry breaking, and universality classes developed by investigators like Lev Landau and Philip W. Anderson. The discipline interacts with areas such as Quantum field theory (in the form of effective field theories), Statistical mechanics, and increasingly with Quantum information science.
Quantum foundations in condensed matter rely on microscopic Hamiltonians and effective models to describe interacting electrons, spins, and phonons. Prototypical models include the Ising model, Heisenberg model, Hubbard model, and BCS theory of superconductivity introduced by John Bardeen, Leon Cooper, and Robert Schrieffer. Techniques from Many-body theory and Quantum field theory are applied to derive collective modes such as magnons, phonons, and plasmons. Concepts like quasiparticles (Landau's Fermi liquid theory), non-Fermi liquids, and topological band theory (informed by the work of Charles Kane and Shou-Cheng Zhang) link microscopic quantum mechanics to observable properties. Exactly solvable models (e.g., the Bethe ansatz solutions) and integrable systems provide rigorous benchmarks.
Study of materials spans crystalline solids, amorphous solids, liquids, glasses, and complex soft matter. Important classes include conventional and unconventional superconductors (e.g., BCS theory, high-temperature cuprates studied at Bell Labs and Brookhaven National Laboratory), topological insulators and semimetals (work by Charles Kane and Shou-Cheng Zhang), heavy fermion compounds, low-dimensional materials such as graphene and transition metal dichalcogenides, and correlated oxides like the manganites and cuprates. Phases are characterized by order parameters, broken symmetries, and topological invariants; tools from crystallography and experiments at facilities like Argonne National Laboratory and synchrotrons inform phase diagrams and emergent behavior.
Experimental condensed matter physics employs a wide range of probes to measure electronic, magnetic, optical, and structural properties. Techniques include angle-resolved photoemission spectroscopy (ARPES), scanning probe microscopies such as the scanning tunneling microscope (STM) developed by Gerd Binnig and Heinrich Rohrer (Nobel Prize), neutron scattering at reactors and spallation sources, X-ray diffraction and synchrotron radiation, transport measurements (resistivity, Hall effect), and spectroscopies including Raman and infrared. Low-temperature apparatus (dilution refrigerators), high magnetic fields (National High Magnetic Field Laboratory), and clean-room fabrication at centers like IBM Research enable exploration of quantum Hall systems, superconductors, and nanoscale devices. Quantum gas experiments with ultracold atoms in optical lattices provide quantum simulators for models such as the Hubbard model.
Theoretical tools include perturbation theory, mean-field approximations, renormalization group methods pioneered by Kenneth G. Wilson, and diagrammatic techniques. Numerical methods are essential: density functional theory (DFT) for electronic structure, quantum Monte Carlo for strongly correlated systems, tensor network methods such as density matrix renormalization group (DMRG), and dynamical mean-field theory (DMFT). High-performance computing and software packages developed at national labs and universities (e.g., codes used at Argonne National Laboratory and Lawrence Berkeley National Laboratory) enable materials prediction and simulation of quantum phase transitions. Machine learning increasingly complements traditional approaches for materials discovery and analysis.
Condensed matter research underpins semiconductor electronics (development led by firms like Intel and research at Bell Labs), magnetic storage (giant magnetoresistance discovered by Albert Fert and Peter Grünberg), superconducting magnets for medical and research instruments, and emerging quantum technologies including superconducting qubits (pursued by IBM and Google Quantum AI), topological qubits, and spintronics. Photonic crystals, thermoelectrics, and two-dimensional materials (e.g., graphene) are driving new devices in energy, sensing, and communications. Industry–academic partnerships and national laboratories accelerate translation to products and standards.
Major open problems center on mechanisms of high-temperature superconductivity in cuprates and iron pnictides, the nature of quantum spin liquids and fractionalization (study by groups at Princeton University and Columbia University), the classification and manipulation of topological phases, and non-equilibrium quantum dynamics including many-body localization and thermalization. Challenges include predictive design of quantum materials using first-principles methods, scalable quantum computing architectures, and integrating correlated electron physics into device engineering. International collaborations, large facilities such as synchrotrons and neutron sources, and interdisciplinary links to chemistry and materials engineering drive future progress.
Category:Physics Category:Quantum mechanics Category:Materials science