Related Experiment Video
Updated: May 31, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Double negative differential thermal resistance induced by nonlinear on-site potentials
Bao-quan Ai1, Wei-rong Zhong, Bambi Hu
1Laboratory of Quantum Information Technology, ICMP and SPTE, South China Normal University, Guangzhou, China.
Summary
This study reveals double negative differential thermal resistance (NDTR) in 1D lattices. Nonlinear potentials cause heat flux to decrease with increasing temperature differences in specific regions.
Area of Science:
- Condensed matter physics
- Thermal transport phenomena
Background:
- Understanding heat conduction in low-dimensional systems is crucial.
- Nonlinear potentials significantly influence thermal transport properties.
Purpose of the Study:
- To investigate heat conduction in 1D homogeneous lattices with nonlinear on-site potentials.
- To identify conditions leading to negative differential thermal resistance (NDTR).
Main Methods:
- Theoretical study of heat conduction.
- Analysis of 1D homogeneous lattices with bounded and unbounded nonlinear on-site potentials.
- Inclusion of harmonic interaction potentials.
Main Results:
- Observed double negative differential thermal resistance (NDTR).
- NDTR occurs in two distinct temperature difference regions.
- Low-temperature NDTR is linked to the bounded nonlinear potential part.
- High-temperature NDTR is attributed to the unbounded nonlinear potential part.
- Nonlinearity of on-site potentials is essential for NDTR in harmonic lattices.
- NDTR can occur without on-site potentials in anharmonic lattices (e.g., rotator model).
Conclusions:
- Nonlinear on-site potentials are key drivers of NDTR in harmonic 1D lattices.
- The nature of nonlinearity (bounded vs. unbounded) dictates NDTR at different temperature ranges.
- Anharmonic lattices exhibit NDTR even with simpler interaction potentials.
Related Concept Videos
01:11P-N junction
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
01:16Biasing of P-N Junction
The operation of a p-n junction diode involves various biasing conditions, including forward bias, reverse bias, and equilibrium.
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
In equilibrium, no external voltage is applied across the p-n junction. The depletion region is formed at the junction interface due to the diffusion of carriers, which leaves behind charged dopants, acceptors on the p-side, and donors on the n-side. These immobile charges create an electric field that prevents further diffusion of carriers. The related energy band...
01:30The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
01:26Linear Approximation in Frequency Domain
Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar.
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear.
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear.
01:28Induced Electric Dipoles
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
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.