Related Experiment Video
Updated: Dec 21, 2025
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
10.1K
Magnetic quantum phase transitions in Kondo lattices
Qimiao Si1, Jian-Xin Zhu, D R Grempel
1Department of Physics and Astronomy, Rice University, Houston, TX 77005-1892, USA.
Summary
Heavy fermion metals exhibit quantum criticality, where magnetic interactions suppress Kondo screening at the quantum critical point (QCP). Extended dynamical mean-field theory reveals a second-order magnetic transition, contrasting with conventional theories.
Area of Science:
- Condensed Matter Physics
- Quantum Critical Phenomena
Background:
- Heavy fermion metals provide experimental platforms for studying quantum criticality.
- Re-examination of Kondo screening and magnetic interactions in Kondo lattice systems is ongoing.
Purpose of the Study:
- To investigate the interplay between Kondo screening and magnetic interactions in Kondo lattice systems.
- To explore the quantum critical behavior of heavy fermion metals using theoretical models.
Main Methods:
- Extended dynamical mean-field theory (EDMFT) for microscopic studies.
- Analytical epsilon-expansion renormalization group method.
- Numerical simulations for recent results.
Main Results:
- A local quantum critical picture emerges, with suppressed Kondo screening at the magnetic quantum critical point (QCP).
- Significant Fermi surface reconstruction and vanishing coherence scale at the QCP.
- Dynamical spin susceptibility shows omega/T scaling, contrasting with spin density wave theories.
Conclusions:
- The study supports a local quantum critical picture for heavy fermion metals.
- EDMFT, when properly accounting for interactions, predicts a second-order magnetic transition at zero temperature.
More Related Videos
Related Concept Videos
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.2K
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
1.2K
03:02Colors and Magnetism
13.6K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
13.6K
01:03Atomic Nuclei: Nuclear Spin State Overview
1.8K
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
1.8K
01:05Atomic Nuclei: Magnetic Resonance
1.0K
The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external magnetic field, as the spins precess at the Larmor frequency, the excess population results in a net magnetization oriented along the z axis. When a pulse or a short burst of radio waves at the Larmor frequency is applied along the x axis, the coupling of frequencies causes resonance and flips the nuclear spins of the excess population from the...
1.0K
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
2.2K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
2.2K
01:31Ferromagnetism
2.9K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.9K