67 citations · 289 across the 27 of their papers we have counts for
29 papers
Classical Simulation of Lossy Gaussian Boson Sampling beyond Square-Root Regime
Youngrong Lim
Photon loss makes Gaussian boson sampling easier to simulate classically. A standard approach replaces the lossy input by classical light, and it stays accurate while the mean numb…
Polynomial Separation between One-Way and Two-Way LOCC in Discrimination of Maximally Entangled States
Youngrong Lim
One-way local operations and classical communication (LOCC) can fail to distinguish four orthogonal maximally entangled states in every local dimension . We show that every…
Ultimate Information Rate for Quantum Sensing under Multilevel Relaxation
Changhun Oh, Seok Hyung Lie, Youngrong Lim
We determine the ultimate information rate of a relaxing multilevel quantum sensor under unrestricted adaptive control and construct an explicit strategy that attains it. We consid…
Local Gaussian bounds on the non-destructive discrimination of two-mode squeezed states
Mi-Jung So, James Moran, Youngrong Lim +2
Typical measurement setups in quantum systems are destructive, meaning that states are irretrievably altered after measurement. In this work, we analyse non-destructive discriminat…
Quantum Circuit Representation of Combinatorial Matrix Functions
Minhyeok Kang, Gwonhak Lee, Youngrong Lim +1
Permanents, hafnians, and loop-hafnians are combinatorial matrix functions closely related to perfect matchings in graphs. These matrix functions arise in the quantum amplitudes of…
Classical algorithms for measurement-adaptive Gaussian circuits
Changhun Oh, Youngrong Lim
Gaussian building blocks are essential for photonic quantum information processing, and universality can be practically achieved by equipping Gaussian circuits with adaptive measur…
Virtual purification complements quantum error correction in quantum metrology
Hyukgun Kwon, Changhun Oh, Youngrong Lim +3
Quantum resources enable one to achieve quantum-enhanced estimation sensitivity beyond its classical counterpart. Many studies mainly focus on reducing statistical error, under the…
Formulas for Mutually Orthogonal Quantum States in Two-Qubit Systems: Orthogonal Schmidt Decompositions
Yonghae Lee, Youngho Min, Sunghyun Bae +1
We present Schmidt decomposition formulas for mutually orthogonal two-qubit pure states and classify orthonormal sets based on their entanglement structure. First, we derive explic…
Classical algorithms for estimating expectation values in linear-optical circuits
Youngrong Lim, Changhun Oh
We present a classical algorithm for approximating the expectation values of observables in linear-optical circuits with arbitrary product input states, achieving additive-error ac…
Nondestructive discrimination of Bell states between distant parties
Bohdan Bilash, Youngrong Lim, Hyukjoon Kwon +4
Identifying Bell states without destroying it is frequently dealt with in nowadays quantum technologies such as quantum communication and quantum computing. In practice, quantum en…
Trade-off between Information Gain and Disturbance in Local Discrimination of Entangled Quantum States
Youngrong Lim, Minki Hhan, Hyukjoon Kwon
We establish an information gain-disturbance trade-off relation in local state discrimination. Our result demonstrates a fundamental limitation of local strategy to discriminate en…
Efficacy of virtual purification-based error mitigation on quantum metrology
Hyukgun Kwon, Changhun Oh, Youngrong Lim +2
Noise is the main source that hinders us from fully exploiting quantum advantages in various quantum informational tasks. However, characterizing and calibrating the effect of nois…
Approximating outcome probabilities of linear optical circuits
Youngrong Lim, Changhun Oh
Quasiprobability representation is an important tool for analyzing a quantum system, such as a quantum state or a quantum circuit. In this work, we propose classical algorithms spe…
Quantum-inspired classical algorithm for molecular vibronic spectra
Changhun Oh, Youngrong Lim, Yat Wong +2
We have recently seen the first plausible claims for quantum advantage using sampling problems such as random circuit sampling and Gaussian boson sampling. The obvious next step is…
Classical simulation of boson sampling based on graph structure
Changhun Oh, Youngrong Lim, Bill Fefferman +1
Boson sampling is a fundamentally and practically important task that can be used to demonstrate quantum supremacy using noisy intermediate-scale quantum devices. In this work, we…
Polynomial T-depth Quantum Solvability of Noisy Binary Linear Problem: From Quantum-Sample Preparation to Main Computation
Wooyeong Song, Youngrong Lim, Kabgyun Jeong +4
The noisy binary linear problem (NBLP) is known as a computationally hard problem, and therefore, it offers primitives for post-quantum cryptography. An efficient quantum NBLP algo…
Quantum Metrological Power of Continuous-Variable Quantum Networks
Hyukgun Kwon, Youngrong Lim, Liang Jiang +2
We investigate the quantum metrological power of typical continuous-variable (CV) quantum networks. Particularly, we show that most CV quantum networks provide an entanglement to q…
Classical simulation of bosonic linear-optical random circuits beyond linear light cone
Changhun Oh, Youngrong Lim, Bill Fefferman +1
Sampling from probability distributions of quantum circuits is a fundamentally and practically important task which can be used to demonstrate quantum supremacy using noisy interme…
Quantum secure learning with classical samples
Wooyeong Song, Youngrong Lim, Hyukjoon Kwon +5
Studies addressing the question "Can a learner complete the learning securely?" have recently been spurred from the standpoints of fundamental theory and potential applications. In…
Quantum solvability of noisy linear problems by divide-and-conquer strategy
Wooyeong Song, Youngrong Lim, Kabgyun Jeong +5
Noisy linear problems have been studied in various science and engineering disciplines. A class of "hard" noisy linear problems can be formulated as follows: Given a matrix $\hat{A…
Upper bounds on the quantum capacity for general attenuator and amplifier
Youngrong Lim, Soojoon Lee, Jaewan Kim +1
There have been several upper bounds on the quantum capacity of the single-mode Gaussian channels with thermal noise, such as thermal attenuator and amplifier. We consider a class…
Activation and superactivation of single-mode Gaussian quantum channels
Youngrong Lim, Ryuji Takagi, Gerardo Adesso +1
Activation of quantum capacity is a surprising phenomenon according to which the quantum capacity of a certain channel may increase by combining it with another channel with zero q…
Universal upper bounds for Gaussian information capacity
Kabgyun Jeong, Hun Hee Lee, Youngrong Lim
The most natural way to describe an information-carrying system containing a specific noise is an additive white Gaussian-noise (AWGN) channel. In bosonic quantum systems (especial…
Activation of quantum capacity of Gaussian channels
Youngrong Lim, Soojoon Lee
Quantum channels can be activated by a kind of channels whose quantum capacity is zero. This activation effect might be useful to overcome noise of channels by attaching other chan…