Optomechanical Quantum Entanglement

As classical technology approaches its limits, exploration of quantum technologies is critical. Quantum optics will be the basis of various cutting-edge research and applications in quantum technology. In particular, quantum optics quite efficacious when applied to quantum networks and the quantum internet. Quantum Optomechanics, a subfield of quantum optics, contains some novel methods for entanglement generation. These entanglement production methods exploit the noise re-encoding process, which is most often associated with creating unwanted phase noise in optical circuits. Using the adapted two-photon formalism and experimental results, we simulate (in an experimentally viable parameter space) optomechanical entanglement generation experiments. These simulations consider dual coherent field input, displaced single-mode squeezed input, and displaced two-mode squeezed inputs. Unsqueezed inputs should yield an $E_N$ of about 0.1 at room temperature, although very high measurement certainty is needed to observe this in the laboratory. Squeezing the displaced input fields increases the expected output entanglement significantly (maximum of $E_N$ of about 1). Furthermore, when considering dual two-mode squeezed input (4 fields) in the simulation, the optomechanical cavity demonstrates squeezing angle-dependent entanglement distribution

Classifying topology in photonic heterostructures with gapless environments

Photonic topological insulators exhibit bulk-boundary correspondence, which requires that boundary-localized states appear at the interface formed between topologically distinct insulating materials. However, many topological photonic devices share a boundary with free space, which raises a subtle but critical problem as free space is gapless for photons above the light-line. Here, we use a local theory of topological materials to resolve bulk-boundary correspondence in heterostructures containing gapless materials and in radiative environments. In particular, we construct the heterostructure's spectral localizer, a composite operator based on the system's real-space description that provides a local marker for the system's topology and a corresponding local measure of its topological protection; both quantities are independent of the material's bulk band gap (or lack thereof). Moreover, we show that approximating radiative outcoupling as material absorption overestimates a heterostructure's topological protection. As the spectral localizer is applicable to systems in any physical dimension and in any discrete symmetry class, our results show how to calculate topological invariants, quantify topological protection, and locate topological boundary-localized resonances in topological materials that interface with gapless media in general.Comment: 6 pages, 4 figures, Supplemental Materia

Optomechanical entanglement at room temperature: A simulation study with realistic conditions

Quantum entanglement is the key to many applications like quantum key distribution, quantum teleportation, and quantum sensing. However, reliably generating quantum entanglement in macroscopic systems has proven to be a challenge. Here, we present a detailed analysis of ponderomotive entanglement generation in a movable-end-mirror-type optomechanical cavity. These cavities utilize optomechanical interactions between the intracavity field and the end mirror to create quantum correlations. We numerically calculate an entanglement measure, the logarithmic negativity, for the quantitative assessment of the entanglement. Experimental limitations, including thermal noise and optical loss, from measurements of an existing experiment were included in the calculation, which is intractable to solve analytically. This analysis shows that lowering optical losses and measurement uncertainties is more important than temperature for observation of the entanglement in movable-end-mirror-type optomechanical cavity experiments. This work will play an important role in the development of ponderomotive entanglement devices

Optomechanical entanglement at room temperature: a simulation study with realistic conditions

Quantum entanglement is the key to many applications like quantum key distribution, quantum teleportation, and quantum sensing. However, reliably generating quantum entanglement in macroscopic systems has proved to be a challenge. Here, we present a detailed analysis of ponderomotive entanglement generation which utilizes optomechanical interactions to create quantum correlations. We numerically calculate an entanglement measure -- the logarithmic negativity -- for the quantitative assessment of the entanglement. Experimental limitations, including thermal noise and optical loss, from measurements of an existing experiment were included in the calculation, which is intractable to solve analytically. This work will play an important role in the development of ponderomotive entanglement devices

Maternal experiences of ethnic discrimination and subsequent birth outcomes in Aotearoa New Zealand

Background Interpersonal discrimination experience has been associated with adverse birth outcomes. Limited research has evaluated this relationship within multicultural contexts outside the United States where the nature and salience of discrimination experiences may differ. Such research is important in order to help identify protective and risk factors that may mediate the relationship between discrimination experience and adverse birth outcomes. Methods Evaluated the relationship between perceived discrimination, as measured in pregnancy, with birth weight and gestation length among Māori, Pacific, and Asian women from Aotearoa New Zealand (N = 1653). Results Thirty percent of the sample reported some type of unfair treatment that they attributed to their ethnicity. For Māori women specifically, unfair treatment at work (β = − 243 g) and in acquiring housing (β = − 146 g) were associated with lower birth weight when compared to Māori women not experiencing these types of discrimination, while an ethnically motivated physical attack (β = − 1.06 week), and unfair treatment in the workplace (β = − 0.95 week), in the criminal justice system (β = − 0.55 week), or in banking (β = − 0.73 week) were associated with significantly shorter gestation. Conclusions Despite a high prevalence of discrimination experience among women from all ethnic groups, discrimination experience was a strong predictor of lower birth weight and shorter gestation length among indigenous Māori women only. Additional research is needed to better understand the risk and protective factors that may moderate the relationship between discrimination experience and adverse birth outcomes among women from different ethnic groups