Related Experiment Video
Updated: Sep 16, 2025
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
8.6K
Finite-time scaling beyond the Kibble-Zurek prerequisite in Dirac systems
Zhi Zeng1,2, Yin-Kai Yu1,2,3,4, Zhi-Xuan Li1,2
1Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, Guangzhou, 510275, China.
Nature Communications
|July 4, 2025
Summary
The Kibble-Zurek mechanism now applies to systems with gapless initial states, generalizing critical dynamics theory. This study validates finite-time scaling for Dirac systems, expanding understanding of quantum critical phenomena.
Area of Science:
- Condensed Matter Physics
- Quantum Dynamics
- Statistical Mechanics
Background:
- The Kibble-Zurek mechanism describes defect formation during phase transitions.
- Finite-time scaling offers universal descriptions from gapped initial states.
- Two-dimensional Dirac systems feature semimetal and Mott insulator phases.
Purpose of the Study:
- Investigate driven critical dynamics in 2D Dirac systems.
- Determine if finite-time scaling applies to gapless initial states.
- Generalize the Kibble-Zurek mechanism for fermionic systems.
Main Methods:
- Analysis of driven critical dynamics.
- Application of finite-time scaling theory.
- Theoretical modeling of Dirac systems.
Main Results:
- Driven dynamics in 2D Dirac systems are captured by finite-time scaling, even from a gapless initial state.
- A criterion for Kibble-Zurek mechanism validity with gapless states is proposed.
- The Kibble-Zurek theory is generalized to include composite fluctuations.
Conclusions:
- The Kibble-Zurek mechanism's applicability is extended to systems with gapless initial states.
- This work provides new insights into non-equilibrium critical dynamics.
- The findings offer a method to study quantum critical properties in fermionic systems.
Related Concept Videos
01:24Properties of DTFT I
519
In signal processing, Discrete-Time Fourier Transforms (DTFTs) play a critical role in analyzing discrete-time signals in the frequency domain. Various properties of the DTFTs such as linearity, time-shifting, frequency-shifting, time reversal, conjugation, and time scaling help understand and manipulate these signals for different applications.
The linearity property of DTFTs is fundamental. If two discrete-time signals are multiplied by constants a and b respectively, and then combined to...
The linearity property of DTFTs is fundamental. If two discrete-time signals are multiplied by constants a and b respectively, and then combined to...
519
01:17Properties of the z-Transform I
316
The z-transform is a fundamental tool in digital signal processing, enabling the analysis of discrete-time systems through its various properties. It is an invaluable tool for analyzing discrete-time systems, offering a range of properties that simplify complex signal manipulations. One fundamental property is linearity. For any two discrete-time signals, the z-transform of their linear combination equals the same linear combination of their individual z-transforms. This property is essential...
316
01:23Linear time-invariant Systems
438
A system is linear if it displays the characteristics of homogeneity and additivity, together termed the superposition property. This principle is fundamental in all linear systems. Linear time-invariant (LTI) systems include systems with linear elements and constant parameters.
The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be...
The input-output behavior of an LTI system can be fully defined by its response to an impulsive excitation at its input. Once this impulse response is known, the system's reaction to any other input can be...
438
01:24BIBO stability of continuous and discrete -time systems
525
System stability is a fundamental concept in signal processing, often assessed using convolution. For a system to be considered bounded-input bounded-output (BIBO) stable, any bounded input signal must produce a bounded output signal. A bounded input signal is one where the modulus does not exceed a certain constant at any point in time.
To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system....
To determine the BIBO stability, the convolution integral is utilized when a bounded continuous-time input is applied to a Linear Time-Invariant (LTI) system....
525
01:18Second Order systems II
173
In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero.
173
01:26Scaling
324
In designing and analyzing filters, resonant circuits, or circuit analysis at large, working with standard element values like 1 ohm, 1 henry, or 1 farad can be convenient before scaling these values to more realistic figures. This approach is widely utilized by not employing realistic element values in numerous examples and problems; it simplifies mastering circuit analysis through convenient component values. The complexity of calculations is thereby reduced, with the understanding that...
324