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Kyle Boschen completed his Honours project in 2022 and is now undertaking a PhD in CI Jeff Davis‘ group. He is investigating the properties of two dimensional semiconducting TMDs using ultrafast spectroscopy. The project fits the FLEET Enabling Research Theme 2, Exciton Superfluids

Magnetic proximity between topological insulators and magnetic insulators is expected to yield interesting states such as the quantum anomalous Hall insulator or axion insulator. In this work, we demonstrate progress towards the creation and characterisation of such structures through transferred MBE TI growths onto MIs, or direct growths on MIs. About the presenter Matthew Gebert is a PhD student in …

Quantum gases with internal degrees of freedom give access to novel quantum vortex phases due to the interplay of mass and spin density-density interactions. Spin-1 Bose-Einstein condensates facilitate unusual vortex phenomenology as they are able to host different ground state phases which can in turn support vortex configurations which support higher and even fractional winding numbers, such as polar core …

About the presenter Mateusz is a Research Fellow in CI Elena Ostrovskaya‘s group. He received his PhD at the University of Warsaw in Poland where he worked on microcavities filled with liquid crystals. His work fits the FLEET Research Theme 2, Exciton Superfluids.

The electron skew scattering by impurities is one of the major mechanisms causing the anomalous Hall effects in semiconductor nanostructures. In this Letter, we argue that in plasmonic setups the skew scattering of plasma waves can be engineered to be giant and observed directly via near-field probes. In particular, we consider the scattering of plasma waves in gated two-dimensional electron …

Here, we demonstrate up-conversion photoluminescence of optically forbidden (dark) excitons in few-layer transition metal dichalcogenides. Transition metal dichalcogenides were mechanically exfoliated onto sapphire substrates using a dry transfer technique. We show that the resonance between up-converted excitons and the bright exciton state at Γ valley results in a strongly enhanced photoluminescence, evidenced by temperature, layer and excitation dependent photoluminescence measurements. …

Overview of recent exciting results on room temperature condensation of exciton-polaritons and Optical Pump Terahertz Probe (OPTP) results in graphene. About the presenter Gary Beane is a Research Fellow working with A/Prof Agustin Schiffrin at Monash University, where he is investigating optically driven topological phases of matter using terahertz time domain spectroscopy and ultrafast pump-probe spectroscopy. He is mainly involved …

Liquid metal alloys are an ever growing industry with a myriad of potential applications such as catalysis, and electronics.1 Unfortunately, the full potential of these materials are under-utilised and is outside the scope of other research parameters.2 Herein, nanodroplet alloyed materials are probed and investigated with the use of a Transmission Electron Microscope (TEM), thus unlocking the potential these materials …

I will present on recent results in our group on 1) room temperature condensation of exciton-polaritons in perovskite-DBR microcavities and 2) Broadband optical-pump THz probe (OPTP) results with graphene. About the presenter Gary Beane is a Research Fellow working with A/Prof Agustin Schiffrin at Monash University, where he is investigating optically driven topological phases of matter using terahertz time domain …

About the presenter Brendan is working with CI Meera Parish to investigate the dynamics of excitons in two-dimensional semiconductors, with a particular focus on spectroscopic probes and the effect of electron doping or large carrier densities. to characterise the topology of an exciton-polariton system and to show how to calculate and measure its quantum geometric tensor (including complex Berry curvature). …

About the presenter Yow-Ming (Robin) Hu is a PhD student working with Chief Investigator Elena Ostrovskaya. Her project aims to characterise the topology of an exciton-polariton system and to show how to calculate and measure its quantum geometric tensor, including complex Berry curvature. This works towards a key objective of FLEET Research Theme 2 Exciton Superfluids to observe, theoretically and …

Optical properties of dark excitons in transition metal dichalcogenides (TMDs) have been received lots of attention due to its significant role in fundamental properties of exciton physics. Here, we demonstrate up-converted photoluminescence (PL) in few-layer WSe2 through exciton-exciton annihilation of intervalley dark excitons. WSe2 was mechanically exfoliated onto silicon substrates with 285-nm-thick SiO2 using a dry transfer technique. We performed …

About the presenter Bianca is a PhD candidate in CI Elena Ostrovskaya‘s group. Her project aims to realise, experimentally, exciton polaritons in artificial lattices and observe novel topologically protected states. This work fits the FLEET Enabling Research Theme 2, Exciton Superfluids.

About the presenter Mitko Oldfield is an experimental physicist specialising in terahertz time-domain spectroscopy and exciton-polariton condensation, working with A/Prof Agustin Schiffrin and Dr Gary Beane at Monash University within FLEET’s research theme 2 and research theme 3. Mikto’s research focuses on forming a polariton condensate in high Q-factor microcavities through the use of a terahertz pumping beam generated via …

Quantum gases with internal degrees of freedom give access to novel quantum vortex phases due to the interplay of mass and spin density-density interactions. Spin-1 Bose-Einstein condensates facilitate unusual vortex phenomenology as they are able to host different ground state phases which can in turn support vortex configurations with higher and even fractional winding numbers, such as polar core and …

About the presenter Dr Eliezer Estrecho is a DECRA Fellow at the Australian National University and a Research Fellow of FLEET. His research interests are mainly on exciton-polariton condensates, non-Hermitian physics, and strong light-matter interaction, specifically between electronic excitations (excitons) and photonic modes.

The quantum kicked rotor (QKR) is a system used to explore quantum chaos, which is extensively studied theoretically and experimentally. The QKR also has many flavours such as the single kicked rotor revealing localisation, delocalisation and anti-resonant behaviours. Moreover, it has the ability to expand to higher dimensions by the modulation of the kick strength with incommensurate frequencies resulting in …

Optical properties of dark excitons in transition metal dichalcogenides (TMDs) have been received lots of attention due to its significant role in fundamental properties of exciton physics. Here, we demonstrate up-converted photoluminescence (PL) in n-layer WSe2 (n > 2) through exciton-exciton annihilation of dark excitons. Few-layer WSe2 were mechanically exfoliated onto silicon substrates with 285-nm-thick SiO2 using a dry transfer …

Quasiparticles with Weyl dispersion can display an abundance of novel topological, thermodynamic and transport phenomena, which is why novel Weyl materials and platforms for Weyl physics are being intensively looked for in electronic, magnetic, photonic and acoustic systems. We demonstrate that conducting materials in magnetic fields generically host Weyl excitations due to the hybridization of phonons with helicons, collective neutral …

Exciton-polaritons (polaritons herein) are bosonic quasiparticles formed when an exciton is coupled to a cavity photon in a semiconductor microcavity [1]. These hybrid light-matter quasiparticles form Bose-Einstein condensates at elevated temperatures due to their very small effective mass. However, polariton condensates are inherently non-equilibrium because of the ultrashort lifetime of polaritons and coexistence with a reservoir of high-energy excitons feeding …

Monolayer tungsten diselenide (1L-WSe2) has recently received attention because of its favourable band structure for probing novel correlated phenomena of p-type carriers, such as interaction-driven and topological insulating phases and superconductivity in twisted bilayers, and Bose-Einstein condensation of excitons in double-layer heterostructures. However, electrical transport studies have been impeded by the lack of a reliable method to realize Ohmic hole-conducting …

Atomically-thin InSe exhibited strong PL emission from its dark excitons due to efficient acoustic-phonon-exciton coupling, resulting in high population density and efficient radiative recombination. The asymmetric lineshape observed in the PL emission is explained by the carrier localization model, attributed to nonuniform surface potentials. About the presenter Shao-Yu Chen is a Scientific Associate Investigator from the National Taiwan University, collaborating …

We investigate the formation of excitons bound by photons using a microscopic Hamiltonian involving quantum well electrons, holes, and microcavity photons. The negative reduced effective mass of the quantum well electron-hole (e-h) pair prevents Coulomb bound excitonic states, but the microcavity photon is capable of inducing binding. Using a theory based on Green’s functions we have calculated the spectral response …

About the presenter Mitko Oldfield is an experimental physicist specialising in terahertz time-domain spectroscopy and exciton-polariton condensation, working with A/Prof Agustin Schiffrin and Dr Gary Beane at Monash University within FLEET’s research theme 2 and research theme 3. Mikto’s research focuses on forming a polariton condensate in high Q-factor microcavities through the use of a terahertz pumping beam generated via …