activity
20122025
most cited400%/W second harmonic conversion efficiency in -diameter gallium phosphide-on-oxide resonators

67 citations · 103 across the 16 of their papers we have counts for

collaborators

21 papers

math.GR2025

Fixed subgroups of generalised Baumslag-Solitar groups

Oli Jones, Alan Logan

We investigate fixed subgroups of automorphisms of generalised Baumslag-Solitar (GBS) groups. Our main results are for automorphisms leaving a Bass-Serre tree invariant, under the…

physics.optics2023

Selective active resonance tuning for multi-mode nonlinear photonic cavities

Alan D. Logan, Nicholas S. Yama, Kai-Mei C. Fu

Resonant enhancement of nonlinear photonic processes is critical for the scalability of applications such as long-distance entanglement generation. To implement nonlinear resonant…

math.GR2022

Post's correspondence problem for hyperbolic and virtually nilpotent groups

Laura Ciobanu, Alex Levine, Alan D. Logan

Post's Correspondence Problem (the PCP) is a classical decision problem in theoretical computer science that asks whether for pairs of free monoid morphisms t…

math.GR2022★ 2 cited

The Conjugacy Problem for ascending HNN-extensions of free groups

Alan D. Logan

We give an algorithm to solve the Conjugacy Problem for ascending HNN-extensions of free groups. To do this, we give algorithms to solve certain problems on dynamics of free group…

physics.optics2022★ 22 cited

Triply-Resonant Sum Frequency Conversion with Gallium Phosphide Ring Resonators

Alan D. Logan, Shivangi Shree, Srivatsa Chakravarthi +5

We demonstrate quasi-phase matched, triply-resonant sum frequency conversion in 10.6-um-diameter integrated gallium phosphide ring resonators. A small-signal, waveguide-to-waveguid…

math.GR2022

The Surface Group Conjectures for groups with two generators

Giles Gardam, Dawid Kielak, Alan D. Logan

The Surface Group Conjectures are statements about recognising surface groups among one-relator groups, using either the structure of their finite-index subgroups, or all subgroups…