Speaker
Description
In chaotic dynamics, the eigenstate thermalization hypothesis (ETH) posits that quantum systems evolve toward an equilibrium state over time, regardless of their initial state. Equivalently, the expectation value of an observable with few degrees of freedom will relax towards a thermal value despite the wavefunction evolving through time [1]. However, there exist quantum mechanical phenomena that violate the ETH, such as quantum chaos, which is the focus of this research.
In this work, we explore quantum chaotic behaviour in disordered materials through simulations inspired by quantum computational algorithms. We leverage the power of quantum-inspired algorithms to simulate the dynamics shown by inconsistent atomic arrangements of disordered materials. Such structures create thermal properties that violate the ETH. This work explores the properties originating from quantum chaos.
Quantum chaos studies chaos theory in quantum mechanical systems. Quantum chaotic dynamics manifest themselves in non-ergodic features called quantum birthmarks, which are probability density enhancements of initial quantum states and their subsequent time-evolved states. This probability density localization in the quantum phase space shows that the system does not relax into an equilibrium state at long times, which is a violation of the ETH. [2] Scarred quantum systems have quantum birthmarks on eigenstates exhibiting an increased probability density along unstable periodic orbits. Consequently, quantum revival, the periodic return of the initial state, occurs without further exploration of the phase space during thermalization. [1]
In this work, we investigate quantum chaotic behaviour by simulating the time evolution of scarred Hamiltonians and Hamiltonians built via random matrix theory (RMT). RMT is a framework used to generate random matrices following Wigner-Dyson level spacing statistics for quantum chaotic systems. To simulate such large matrices, we use quantum computing algorithms such as Trotterization and variational quantum algorithms. We further expand our research to many-body chaotic behaviours to investigate the dynamical properties of disordered materials.
References
[1] M. Srihari and A. Shaji, arXiv:2503.11616 (14 March 2025).
[2] A. M. Graf et al., arXiv:2412.02982 (4 December 2024).
| Keyword-1 | Quantum Chaos |
|---|---|
| Keyword-2 | Quantum Computing |
| Keyword-3 | Disordered Materials |