Related Experiment Video
Updated: Jul 7, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Quantum phase transition in the two-band hubbard model.
1Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany.
Physical Review Letters
|February 1, 2008
Summary
Researchers explored electronic states in strongly correlated materials using advanced computational methods. A new quantum phase transition was discovered in a specific material phase relevant to transition metal oxides.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Strongly correlated materials exhibit complex electronic behaviors due to electron-electron interactions.
- Understanding the interplay between itinerant and localized electronic states is crucial for designing novel materials.
- The orbital-selective Mott phase presents unique challenges in theoretical modeling.
Purpose of the Study:
- To investigate the interaction between itinerant and Mott localized electronic states.
- To explore the phase diagram of the two-band Hubbard model.
- To identify novel quantum phase transitions in strongly correlated systems.
Main Methods:
- Dynamical Mean Field Theory (DMFT) was employed to model electron correlations.
- Numerical Renormalization Group (NRG) method was combined with DMFT for accurate calculations.
- The two-band Hubbard model was used as the theoretical framework.
Main Results:
- A novel nonmagnetic quantum phase transition was identified.
- This transition occurs at zero temperature within the bad-metallic orbital-selective Mott phase.
- The findings are relevant for parameter values of Hund's exchange typical in transition metal oxides.
Conclusions:
- The study reveals a previously unknown quantum phase transition in a relevant material class.
- The results advance the understanding of electronic behavior in strongly correlated systems.
- This discovery has implications for the design and application of transition metal oxides.
Related Concept Videos
01:21Phase Transitions
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
02:31Phase Transitions
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
02:18The Bohr Model
Following the work of Ernest Rutherford and his colleagues in the early twentieth century, the picture of atoms consisting of tiny dense nuclei surrounded by lighter and even tinier electrons continually moving about the nucleus was well established. This picture was called the planetary model since it pictured the atom as a miniature “solar system” with the electrons orbiting the nucleus like planets orbiting the sun. The simplest atom is hydrogen, consisting of a single proton as the nucleus...
02:45The Quantum-Mechanical Model of an Atom
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra. Schrödinger...
01:01Energy Bands in Solids
Isolated atoms have discrete energy levels that are well described by the Bohr model. And, it quantifies the energy of an electron in a hydrogen atom as En. Higher quantum numbers 'n' yield less negative, closer electron energy levels.
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states that no two...
Band Formation:
When atoms are brought close together, as in a solid, these discrete energy levels begin to split due to the overlap of electron orbitals from adjacent atoms. This split occurs because of the Pauli exclusion principle, which states that no two...
01:12Fermi Level Dynamics
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...