Research Groups

▶ Our group aims to introduce multidisciplinary viewpoints on wave mechanics and its applications to intelligent systems.

- Wave mechanics cover a variety of fields in physics, from classical to quantum phenomena. Despite the different specific properties of each field, there exists the mathematical similarity in various wave mechanics, including photonics, quantum mechanics, acoustics, elastic waves, and electronic circuits.

- This underlying similarity inspires the multidisciplinary connection between different waves, as demonstrated in the research of quantum-optical analogy, acoustic topology, non-Hermitian electronic circuits, and the quantum analogy of elastic waves. Furthermore, this multidisciplinary viewpoint can be more generalized to network theory, biomimetics, and machine learning.

- Based on this multidisciplinary perspective, we try to (i) devise new design strategies for wave systems, (ii) reveal novel wave phenomena, and (iii) achieve superior device performance. The research goal of our laboratory is the realization of "intelligent wave systems," ultimately focusing on the construction of wave-based artificial intelligence: ultra-fast inference, ultra-low power consumption, and reasonable feature sizes.

In detail, we are now focusing on achieving the neuromorphic realization of intelligent photonic systems: "Thinking with Light."

▶ Photonic AI
- Scale-Free photonic neural networks
- Photonic neurons/synapses
- Photonic activation functions

▶ Photonic Quantum Computing
- Quantum machine learning
- Open quantum systems
- Graph theory for quantum optics

▶ AI Wave Mechanics
- Convolutional Neural Networks (CNNs) for wave-matter interactions
- Graph Neural Networks (GNNs) for wave-matter interactions
- Scale invariance in neural networks and engineered materials

▶ Disordered Photonics
- Engineered disorder in photonics
- Crystal-like spectra/scattering in disordered materials
- Scale-free materials with hub dynamics

▶ Open-System/Non-Euclidean/Topological Photonics
- Chirality, oscillation quenching, and topology in open systems
- Hyperbolic lattices and their topology & deformations
- Flat-band photonics

[17] Gyunghun Kim, Jensen Li, Xianji Piao*, Namkyoo Park*, Sunkyu Yu*. Programmable lattices for non-Abelian topological photonics and braiding.
Physical Review Letters 136, 043804 (2026)

[16] Gyunghun Kim, Joseph Suh, Dayeong Lee, Namkyoo Park* & Sunkyu Yu*. Long-range-interacting topological photonic lattices breaking channel-bandwidth limit.
Light: Science & Applications 13, 189 (2024)

[15] Xianji Piao, Sunkyu Yu* & Namkyoo Park*. Programmable Photonic Time Circuits for Highly Scalable Universal Unitaries.
Physical Review Letters 132, 103801 (2024)

[14] Joseph Suh, Gyunghun Kim, Hyungchul Park, Shanhui Fan, Namkyoo Park* & Sunkyu Yu*. Photonic Topological Spin Pump in Synthetic Frequency Dimensions.
Physical Review Letters 132, 033803 (2024)

[13] Sunkyu Yu* & Namkyoo Park*. Heavy tails and pruning in programmable photonic circuits for universal unitaries.
Nature Communications 14, 1853 (2023)

[12] Jungmin Kim, Dayeong Lee, Sunkyu Yu* & Namkyoo Park*. Unidirectional scattering with spatial homogeneity using correlated photonic time disorder.
Nature Physics 19, 726 (2023)

[11] Sunkyu Yu*. Evolving scattering networks for engineering disorder.
Nature Computational Science 3, 128-138 (2023)
: Highlighted in News & Views, Nat. Comput. Sci. & Cover Paper

[10] Sunkyu Yu†, Cheng-Wei Qiu†, Yidong Chong, Salvatore Torquato* & Namkyoo Park*. Engineered Disorder in Photonics.
Nature Reviews Materials 6, 226 (2021): Invited Review Article

[09] Sunkyu Yu, Xianji Piao & Namkyoo Park*. Machine learning identifies scale-free properties in disordered materials.
Nature Communications 11, 4842 (2020)

[08] Sunkyu Yu*, Xianji Piao & Namkyoo Park*. Topological Hyperbolic Lattices.
Physical Review Letters 125, 053901 (2020): Cover Paper

[07] Sunkyu Yu, Xianji Piao & Namkyoo Park*. Neuromorphic Functions of Light in Parity‐Time‐Symmetric Systems.
Advanced Science 6, 1900771 (2019): Cover Paper

[06] Sunkyu Yu, Xianji Piao & Namkyoo Park*. Bohmian Photonics for Independent Control of Phase and Amplitude of Waves.
Physical Review Letters 120, 193902 (2018)

[05] Sunkyu Yu, Xianji Piao, Jiho Hong & Namkyoo Park*. Metadisorder for designer light in random systems.
Science Advances 2, e1501851 (2016)

[04] Sunkyu Yu†, Hyun Sung Park†, Xianji Piao, Bumki Min & Namkyoo Park*. Low-dimensional optical chirality in complex potentials.
Optica 3, 1025 (2016): Cover Paper

[03] Sunkyu Yu, Xianji Piao, Jiho Hong & Namkyoo Park*. Interdimensional optical isospectrality inspired by graph networks.
Optica 3, 836 (2016)

[02] Sunkyu Yu, Xianji Piao, Jiho Hong & Namkyoo Park*. Bloch-like waves in random-walk potentials based on supersymmetry.
Nature Communications 6, 8269 (2015)

[01] Kyungjae Chung†, Sunkyu Yu†, Chul-Joon Heo, Jae Won Shim, Seung-Man Yang, Moon Gyu Han, Hong-Seok Lee, Yongwan Jin, Sang Yoon Lee, Namkyoo Park & Jung H. Shin*. Flexible, Angle-Independent Structural Color Reflectors Inspired by Morpho Butterfly Wings.
Advanced Materials 24, 2375 (2012): Cover Paper & Highlighted in Nature