IPS Meeting Day 1

Today was the first day of the IPS Meeting, an annual conference organised by the Institute of Physics Singapore. For many of us in Singapore, this was the first in-person conference we have been able to attend since the pandemic started. The many covid restrictions mean that it's not the same as the pre-pandemic times (mingling between participants not allowed, must stick to the same session room for the whole day), but is still a lot better than online conferences. Big thanks to the organisers for making it run smoothly despite the recent changes to the covid restrictions.

Here are the slides for my talk on applications of persistent homology to physics. I think for many of us (me included) it will take some time to get used to presenting in person again...

Some highlights from Day 1:

• Prof. Jie Yan (NUS) talked about his group's work on developing more sensitive covid antigen and antibody testing, sharing data on how his and his team's antibodies are decaying with time following their vaccination doses...
• Prof. Ranjan Singh (NTU) gave an overview of the importance of terahertz interconnects for 6G communication technologies, including work from last year on terahertz waveguides based on topological edge modes published in Nature Photonics.
• Weikang Wu (NTU) explained how higher-order band crossings (i.e. parabolic and cubic crossings) can emerge in certain two-dimensional systems. For example, cubic crossings can be induced by spin-orbit coupling. arXiv preprint.
• Jeremy Lim (SUTD) on how 3D Dirac semimetals can provide orders of magnitude more efficient high harmonic generation compared to 2D materials, limited mainly by propagation-induced dephasing of the light-induced current. arXiv preprint.
• Xingran Xu (NTU) - Interaction-induced skin effect in exciton-polaritons. The non-Hermitian skin effect (extreme sensitivity of eigenvalues to boundary conditions) most often arises in Hamiltonians with non-reciprocal couplings, which are tricky to realize. By suitably pumping a polariton condensate (such that it exhibits the same nonlinear mode profile for open and periodic boundary conditions), one can also observe the non-Hermitian skin effect in the fluctuation modes of the condensate!
• Udvas Chattopadhyay (NTU, now NUS) - Mode delocalization in a disordered photonic Chern insulator. The most well-known feature of Chern insulators is their protected edge edge states that traverse the bulk band gaps. Interestingly, nonzero Chern numbers also lead to bulk modes protected against localization in the presence of disorder, which can be observed using arrays of coupled microring resonators.
• Anna Paterova (A*STAR) talked about quantum imaging, which enables measurement of objects in troublesome spectral regions (such as the moleculer fingerprint region) using cheaper optical or infrared cameras, based on quantum interference between photon pairs generated by nonlinear crystals. Paper in Science Advances.

Looking forward to attending the Quantum Engineering sessions tomorrow!