The study of forms and patterns in nature is a fascinating one that goes back to antiquity and really evolved into a formal discipline after the pioneering work of D’Arcy Thompson, whose century-old classic “On growth and form” is still in print! Since then, there has been an increasing appreciation of the role in which geometry, elasticity, and topology play in the morphology of things. In this talk, I will present my foray into this wonderful world, and try to bridge perspectives from morphology, ecology, evolution, and development.

Since the first isolation of graphene, devices based on novel low-dimensional materials (LDM) and their heterostructures have become a gold mine for exploring new fundamental phenomena. Reduced dimensionality, peculiar band structures, quantum geometry, and strong quasiparticle interactions in a unique way determine the response of LDM to external fields thereby offering a powerful setting by which to probe novel radiation-matter interaction effects and prototype future optoelectronic technology. In the first (fundamental) part of my talk, we will discuss light-matter interaction effects arising in LDM due to the excitation of plasmons. I will present our recent results on the quasi-relativistic Fizeau drag effect [1]. Predicted by Fresnel in the XIX century and demonstrated by Fizeau, dragging of light by the flow of water was among the cornerstones of Einstein's special relativity. Our experiments on graphene materialized the electronic version of this fundamental effect in which the flow of electrons on par with the moving medium was found to alter the surface plasmon polaritons (SPP) dispersion (Fig. 1). The importance of the observed plasmonic Fizeau drag is that it enables breaking of time-reversal symmetry and reciprocity at infrared frequencies without resorting to magnetic fields or chiral optical pumping. Next, we will discuss peculiar effects arising in graphene plasmonics when the latter is subjected to a perpendicular magnetic field. I will show that graphene supports the propagation of slow Bernstein collective modes whose diverging density of plasmonic states results in strong magnetoabsorption at THz frequencies [2]. In the second (applied) part of my talk, I will show that with a proper processing, atomically thin high-temperature cuprate superconductors can be used in single-photon detection technology. We will discusshow to fabricate superconducting nanowires out of thin flakes of Bi₂Sr₂CaCu₂O_8+δ (BSCCO) and La_1.55Sr_0.45CuO₄/La₂CuO₄ (LSCO-LCO) bilayer films and then, look at their response to visible and infrared light. I will show, that both materials feature single-photon operation above liquid helium temperature as revealed through the linear scaling of the photon count rate on the radiation power. For the BSCCO detectors, we observed single-photon sensitivity at the technologically important 1.5 μm telecommunications wavelength up to 25 K [3].

Fig. 1. Fizeau drag in graphene plasmonics. a, Schematic of a graphene device with a constricted channel. Under the illumination of an infrared laser, the gold launcher excites propagating SPPs, which were visualized by near-field tip-based imaging techniques. Black streamlines represent carrier drift directions. b, SPP line profiles without d.c. current (black) and with Jdc = 0.69 mA μm⁻¹ (blue), illustrating a reduction of the SPP wavelength.

Seven years on from LIGO's first detection of gravitational waves (GWs), astrophysical GW sources are now routinely observed by a growing network of ground-based detectors at both high and low frequencies. In the next decade, space interferometers such as the LISA mission will probe the mid-frequency GW band, where the richest population of sources radiate. My talk today will include a broad update on the present status of ground-based observing, followed by a brief introduction to the distinctive challenges of space-based GW astronomy. I will also discuss how modern computational and statistical techniques are being brought to bear on a variety of open problems in LISA scientific analysis.

Theoretical work has suggested that active galactic nuclei (AGN) play an important role in quenching star formation in massive galaxies. However, direct observational evidence of AGN affecting molecular gas (the fuel for star formation) via outflows is challenging to obtain, particularly at high redshift when cosmic star formation rates were at their highest. Indirect evidence for AGNs’ impact on their host galaxies’ cold gas phase may be provided by measurements of the gas excitation. I will present recent observations of high-excitation CO lines from the Atacama Large Millimeter/submillimeter Array for a small sample of z≈2-6 purely star-forming galaxies and known AGN host galaxies. We find that the CO spectral line energy distributions are somewhat heterogenous, even at high excitation. We will discuss why these objects may have produced such mixed results, and how other observables, such as line widths, may add clarity to the gas heating mechanisms.

There is currently a tremendous global effort invested into building quantum computing technologies. While today's devices are still far from having the fault-tolerance required to perform reliable large-scale computation, they are nevertheless exceptional platforms ideal for the investigation of quantum many-body physics in regimes that go beyond conventional material experiments. This stems from their unprecedented capabilities for control and measurement. In this talk I will demonstrate how such capabilities allow for the probing of a novel phenomenon in dynamics, namely a deeper form of quantum thermalization (the process by which systems settle down over time), in which not just local observables relax to universal values but also conditional post-measurement wave-functions acquire a universally random distribution. Quantum information theoretic concepts are used to characterize this, showing the importance of the union of many-body and quantum information frameworks to yield new insights into fundamental phenomena. Time-permitting, I will sketch how such universal randomness can in fact be used as a resource for applications in quantum information science, like quantum state learning.