Observation of non-Hermitian point gap in photonic crystals
Fuente:
arXiv
Salvato in:
| Autori principali: | , , , , , , , , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2025
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866911323958280192 |
|---|---|
| author | Moritake, Yuto Ogawa, Nozomi Takeda, Issei Ohinata, Yusuke Uemura, Takahiro Yoda, Taiki Takata, Kenta Kuramochi, Eiichi Sumikura, Hisashi Notomi, Masaya |
| author_facet | Moritake, Yuto Ogawa, Nozomi Takeda, Issei Ohinata, Yusuke Uemura, Takahiro Yoda, Taiki Takata, Kenta Kuramochi, Eiichi Sumikura, Hisashi Notomi, Masaya |
| contents | Non-Hermitian point gap (NHPG) is a unique phenomenon in non-Hermitian systems and induces non-Hermitian skin effect (NHSE). In photonic crystals, NHPG and the NHSE have previously been explored mainly through material loss, where the typically low $Q$ factors make direct observation of complex frequencies challenging. Here, we demonstrate the direct experimental observation of an NHPG by using a radiation-loss-based non-Hermitian photonic crystal. Radiation loss can be engineered through structural design, enabling control of the imaginary part of the complex frequency and allowing relatively high $Q$ factors. This approach is compatible with widely used absorption-free silicon-slab photonic crystals. We developed a measurement system that can measure photonic bands along arbitrary lines in $k$-space. Our measurements demonstrated direct observation of the NHPG in photonic crystals, and the reversal of non-Hermitian topology through the flip of loop rotation in a complex plane. Our platform, which requires neither gain media nor synthetic dimensions, establishes radiation-loss engineering as a simple and versatile route for photonic functionality using an NHSE in nanophotonic systems. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_14974 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Observation of non-Hermitian point gap in photonic crystals Moritake, Yuto Ogawa, Nozomi Takeda, Issei Ohinata, Yusuke Uemura, Takahiro Yoda, Taiki Takata, Kenta Kuramochi, Eiichi Sumikura, Hisashi Notomi, Masaya Optics Non-Hermitian point gap (NHPG) is a unique phenomenon in non-Hermitian systems and induces non-Hermitian skin effect (NHSE). In photonic crystals, NHPG and the NHSE have previously been explored mainly through material loss, where the typically low $Q$ factors make direct observation of complex frequencies challenging. Here, we demonstrate the direct experimental observation of an NHPG by using a radiation-loss-based non-Hermitian photonic crystal. Radiation loss can be engineered through structural design, enabling control of the imaginary part of the complex frequency and allowing relatively high $Q$ factors. This approach is compatible with widely used absorption-free silicon-slab photonic crystals. We developed a measurement system that can measure photonic bands along arbitrary lines in $k$-space. Our measurements demonstrated direct observation of the NHPG in photonic crystals, and the reversal of non-Hermitian topology through the flip of loop rotation in a complex plane. Our platform, which requires neither gain media nor synthetic dimensions, establishes radiation-loss engineering as a simple and versatile route for photonic functionality using an NHSE in nanophotonic systems. |
| title | Observation of non-Hermitian point gap in photonic crystals |
| topic | Optics |
| url | https://arxiv.org/abs/2512.14974 |