126 citations · 285 across the 15 of their papers we have counts for
15 papers
Evolution Generators for Complex Parameters
Jen-Yin Yeh, Chia-Yi Ju
Theoretical studies on how quantum systems are affected by external factors are often formulated through parameter changes in the system's Hamiltonian. Beyond Berry connections and…
Non-Hermitian Rayleigh-Schrödinger-like Perturbation Theory at Exceptional Point
Wei-Ming Chen, Chia-Yi Ju
We develop a Rayleigh--Schrödinger-like perturbation theory for non-Hermitian quantum systems at an exceptional point of order . Working in the Jordan basis of the unperturbed H…
Fidelity and quantum geometry approach to Dirac exceptional points in diamond nitrogen-vacancy centers
Chia-Yi Ju, Gunnar Möller, Yu-Chin Tzeng
Dirac exceptional points (EPs) represent a novel class of non-Hermitian singularities that, unlike conventional EPs, reside entirely within the parity-time unbroken phase and exhib…
Heisenberg and Heisenberg-Like Representations via Hilbert Space Bundle Geometry in the Non-Hermitian Regime
Chia-Yi Ju, Adam Miranowicz, Jacob Barnett +2
The equivalence between the Schrödinger and Heisenberg representations is a cornerstone of quantum mechanics. However, this relationship remains unclear in the non-Hermitian regime…
Non-Hermitian Generalization of Rayleigh-Schrödinger Perturbation Theory
Wei-Ming Chen, Yen-Ting Lin, Chia-Yi Ju
While perturbation theories constitute a significant foundation of modern quantum system analysis, extending them from the Hermitian to the non-Hermitian regime remains a non-trivi…
Evidence for Exceptional Points as Topological Defects
Chia-Yi Ju, Szu-Ming Chen
Studies have shown that quantum states reside in a Hilbert space bundle. When a quantum system depends on continuous external parameters, these parameters define additional dimensi…
Quantum State Evolution and Berry Potentials at Exceptional Points and Quantum Phase Transitions
Chia-Yi Ju, Fu-Hsiang Huang
The behavior of quantum states at exceptional points and at critical points associated with quantum phase transitions is intriguing yet puzzling. In this study, we present an alter…
Visually quantifying single-qubit quantum memory
Wan-Guan Chang, Chia-Yi Ju, Guang-Yin Chen +2
To store quantum information, quantum memory plays a central intermediate ingredient in a network. The minimal criterion for a reliable quantum memory is the maintenance of the ent…
Emergent parallel transport and curvature in Hermitian and non-Hermitian quantum mechanics
Chia-Yi Ju, Adam Miranowicz, Yueh-Nan Chen +2
Studies have shown that the Hilbert spaces of non-Hermitian systems require nontrivial metrics. Here, we demonstrate how evolution dimensions, in addition to time, can emerge natur…
Flattening the Curve with Einstein's Quantum Elevator: Hermitization of Non-Hermitian Hamiltonians via a Generalized Vielbein Formalism
Chia-Yi Ju, Adam Miranowicz, Fabrizio Minganti +3
The formalism for non-Hermitian quantum systems sometimes blurs the underlying physics. We present a systematic study of the vielbein-like formalism which transforms the Hilbert sp…
Hunting for the non-Hermitian exceptional points with fidelity susceptibility
Yu-Chin Tzeng, Chia-Yi Ju, Guang-Yin Chen +1
The fidelity susceptibility has been used to detect quantum phase transitions in the Hermitian quantum many-body systems over a decade, where the fidelity susceptibility density ap…
Simplifying 4d Harmonic Superspace
Dharmesh Jain, Chia-Yi Ju, Warren Siegel
We quantize super Yang-Mills action in harmonic superspace using "Fermi-Feynman" gauge and also develop the background field formalism. This leads to simpler propag…
Non-Hermitian Hamiltonians and no-go theorems in quantum information
Chia-Yi Ju, Adam Miranowicz, Guang-Yin Chen +1
Recently, apparent nonphysical implications of non-Hermitian quantum mechanics (NHQM) have been discussed in the literature. In particular, the apparent violation of the no-signali…
Gauging Unbroken Symmetries in F-theory
Chia-Yi Ju, Warren Siegel
F-theory attempts to include all U-dualities manifestly. Unlike its T-dual manifest partner, which is based on string current algebra, F-theory is based on higher dimensional brane…
Systematizing semi-shortening
C. -Y. Ju, W. Siegel
We re-derive semi-shortening conditions for four-dimensional superconformal field theory with a different approach. These conditions have similar patterns that can be generalized t…