2 citations · 2 across the 14 of their papers we have counts for
16 papers
The Classical Boundary of Quantum Computation: History-Resolved Causal Stochastic Machines and the Cost of Classicalization
Kyoungho Cho, Junghee Ryu, Minsu Kim +1
What separates quantum computation from classical computation when a classical model may retain every branch history and arbitrary causal memory? We study this question using histo…
Phase-Flag Access and No-Go Constraints on Quotient-Space Real Quantum Mechanics
Jeongho Bang, Kyoungho Cho, Kyunghyun Baek
Barrios Hita et al. [Phys. Rev. Lett. 136, 240202 (2026)] proposed a quotient-space formulation of quantum mechanics over the real numbers and concluded that complex numbers are on…
Hayden--Preskill recovery at finite temperature on a quantum processor: dynamics and initial state from the SYK model
Jeongho Bang, Moongul Byun, Kyoungho Cho +2
In the original Hayden--Preskill recovery, the post-injection scrambler and initial state are {\it not related}. We extend this setup in two ways: by using a SWAP gate so that the…
Hidden Complex Structure in Quotient-Space Real Quantum Mechanics
Jeongho Bang, Kyoungho Cho, Kyunghyun Baek
Barrios Hita et al. [Phys. Rev. Lett. , 240202 (2026)] argued that quantum mechanics can be formulated over the real numbers by replacing the tensor-product postulate wit…
Breaking the One-Dimensional Expressibility-Trainability Tradeoff
Kyoungho Cho, Yu-Seong Jeon, Jinhyoung Lee +1
Expressive parameterized quantum circuits (PQCs) are often designed under a dilemma: the growth of expressibility and entangling power (EP) that improves Hilbert-space coverage is…
First-Quantized Relativistic Quantum Simulation with Periodic and Dirichlet Boundary Conditions
Jeongho Bang, Timothy P. Spiller, Kyunghyun Baek +2
In this work, we present a methodology for first-quantized relativistic quantum simulation on one-dimensional finite domains under the two boundary conditions most commonly used in…
Quantum Occam Learning: Sample-Supported Expressibility for Circuit-Based Quantum Learning
Jeongho Bang, Kyoungho Cho, Jeongwoo Jae
A central principle in quantum machine learning is that an ansatz should be expressive enough to represent the quantum data of interest. Yet, the expressibility is statistically me…
Learning with Active Quantum Subspaces: Scalable Hybrid Advantage without Full Quantum Data-Encoding
Jeongho Bang, Wooyeong Song, Kyoungho Cho +2
We study whether quantum learning advantage can persist without fully embedding a large classical input into a highly superposed quantum state. To address this question, we introdu…
Universality cost of non-Gaussian enhancement in continuous-variable quantum teleportation: A fidelity--deviation trade-off
Kyoungho Cho, Bongjune Kim, Jeongho Bang
Continuous-variable (CV) quantum teleportation is usually benchmarked by average fidelity, but when the teleportation is repeatedly used within optical networks or measurement-base…
Sharpening Worst-Case Error Assessment for Fault-Tolerant Quantum Computing: Fidelity and Its Deviation
Kyoungho Cho, Ilkwon Sohn, Yongsoo Hwang +1
Gate fidelity -- an average fidelity over all possible input states -- is the workhorse metric for benchmarking quantum gates or circuits, yet fault-tolerant quantum computing ulti…
Physics-Aware Learnability: From Set-Theoretic Independence to Operational Constraints
Jeongho Bang, Kyoungho Cho
Beyond binary classification, learnability can become a logically fragile notion: in EMX, even the class of all finite subsets of is learnable in some models of ZFC and not…
Quantum Interference Needs Convention: Overlap-Determinability and Unified No-Superposition Principle
Jeongho Bang, Kyoungho Cho, Ki Hyuk Yee
Quantum superposition is often phrased as the ability to add state vectors. In practice, however, the physical quantity is a ray (a rank-one projector), so each input specifies onl…
Learning at the Edge of Causality: Optimal Learning-Sample Complexity from No-Signaling Constraints
Jeongho Bang, Kyoungho Cho, Jeongwoo Jae
What ultimately fixes the sample cost of quantum learning -- algorithmic ingenuity or physical law? We study this question in an arena where computation, learning, and causality co…
Witness wedges in fidelity-deviation plane: separating teleportation advantage and Bell-inequality violation
Kyoungho Cho, Jeongho Bang
We develop a unified framework to analyze -dimensional quantum teleportation through the joint geometry of two complementary figures of merit: average fidelity (how well a p…
Fundamental limits to contrast reversal of survival probability correlations
Kyoungho Cho, Jeongho Bang
In measurement design, it is common to engineer anti-contrast readouts -- two measurements that respond as differently as possible to the same inputs so that contributions that aff…
Entangling Power and Its Deviation: A Quantitative Analysis on Input-State Dependence and Variability in Entanglement Generation
Kyoungho Cho, Jeongho Bang
Quantifying the entangling capability of quantum operations is a fundamental task in quantum information science. Traditionally, this capability is measured by the entangling power…