The application of topology in optics has led to a new paradigm in developing photonic devices with robust properties against disorder. Although considerable progress on topological phenomena has been achieved in the classical domain, the realization of strong light-matter coupling in the quantum domain remains unexplored. We demonstrate a strong interface between single quantum emitters and topological photonic states. Our approach creates robust counterpropagating edge states at the boundary of two distinct topological photonic crystals. We demonstrate the chiral emission of a quantum emitter into these modes and establish their robustness against sharp bends. This approach may enable the development of quantum optics devices with built-in protection, with potential applications in quantum simulation and sensing.

Recent studies have established the involvement of the fat mass and obesity-associated gene (FTO) in metabolic disorders such as obesity and diabetes. However, the precise molecular mechanism by which FTO regulates metabolism remains unknown. Here, we used a structure-based virtual screening of U.S. Food and Drug Administration–approved drugs to identify entacapone as a potential FTO inhibitor. Using structural and biochemical studies, we showed that entacapone directly bound to FTO and inhibited FTO activity in vitro. Furthermore, entacapone administration reduced body weight and lowered fasting blood glucose concentrations in diet-induced obese mice. We identified the transcription factor forkhead box protein O1 (FOXO1) mRNA as a direct substrate of FTO, and demonstrated that entacapone elicited its effects on gluconeogenesis in the liver and thermogenesis in adipose tissues in mice by acting on an FTO-FOXO1 regulatory axis.

Long-distance quantum communication relies on the ability to efficiently generate and prepare single photons at telecom wavelengths. In many applications these photons must also be indistinguishable such that they exhibit interference on a beamsplitter, which implements effective photon-photon interactions. However, deterministic generation of indistinguishable single photons with high brightness remains a challenging problem. We demonstrate two-photon interference at telecom wavelengths using an InAs/InP quantum dot in a nanophotonic cavity. The cavity enhances the quantum dot emission, resulting in a nearly Gaussian transverse mode profile with high out-coupling efficiency exceeding 36% after multi-photon correction. We also observe Purcell enhanced spontaneous emission rate up to 4. Using this source, we generate linearly polarized, high purity single photons at 1.3 μm wavelength and demonstrate the indistinguishable nature of the emission using a two-photon interference measurement, which exhibits indistinguishable visibilities of 18% without post-selection and 67% with post-selection. Our results provide a promising approach to generate bright, deterministic single photons at telecom wavelength for applications in quantum networking and quantum communication.* Email: edowaks@umd.edu 2 Single photon sources are important building blocks for optical quantum information processing [1][2][3][4]. They are essential to generate photonic quantum bits (qubits) that can travel long distances over optical fibers and interconnect distant quantum network nodes [5][6][7]. Efficient on-demand single photon sources also enable quantum computation schemes based on either linear [3, 4] or nonlinear [8] optical elements.Many applications in quantum communication require deterministic single-photon sources that emit at telecom wavelengths. Parametric down-conversion sources can operate in this wavelength range [9, 10] but provide only heralded single-photon states and cannot be easily extended to ondemand operation. In contrast, single quantum emitters provide the potential for creating ondemand single-photon sources [11, 12]. Quantum dots in III-V semiconductors are particularly promising quantum emitters that generate single photons with high indistinguishability at nearinfrared wavelengths [13][14][15][16][17][18], and are also compatible with electrical injection [19,20] and integration with nanophotonic structures [21][22][23][24]. A number of works have extended the emission of III-V quantum dots to telecom wavelengths by optimizing materials and growth parameters [25][26][27][28][29][30][31]. However, an on-demand source of indistinguishable single photons remains an outstanding challenge at telecom wavelength.In this work, we demonstrate two-photon interference from a bright single photon source at telecom wavelengths. We use a single InAs/InP quantum dot in a photonic crystal cavity to attain bright and highly polarized single-photon emission at telecom wavelengths. Rather than using the fundamental mode of the ca...

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Plasmonic nano-structures provide an efficient way to control and enhance the radiative properties of quantum emitters. Coupling these structures to single defects in lowdimensional materials provides a particularly promising material platform to study emitterplasmon interactions because these emitters are not embedded in a surrounding dielectric. They can therefore approach a near-field plasmonic mode to nanoscale distances, potentially enabling strong light-matter interactions. However, this coupling requires precise alignment of the

Poly-L-lactide Acid (PLLA), as a credible biodegradable polymer-based material, can provide a promising amount of degradation time for vessel remodeling. Served as a sort of reliable intravascular implants, PLLA stents are expected to provide sufficient scaffolding to the target arteries without generating too much recoil after deployment. Besides, the stress and strain distribution should be as homogeneous as possible, and the stent conformability in fitting to the nature curvature of the vessels needs to be guaranteed. In the present study, mechanical performances of a stent made of PLLA material were investigated based on 3-D finite element method (FEM) and experiment verification. Simulations contained several deformation steps: crimping, spring-back after crimping, expanding and spring-back after expanding. The stent's deformation and stress/strain distributions were analyzed. Several indexes including the radial recoil ratio after crimping and expanding to different sizes, the radial properties including radial strength, the radial stiffness and the collapse pressure were established. In vitro static loading experiments of the stent were conducted as the verification of the FEM results, and a good agreement between them was obtained. Moreover, simulation of three-point bending was performed to assess the bending flexibility of the stent, and bending stiffness was defined as a measurement of structure resistance to the bending deformation.

Coupling of an atom-like emitter to surface plasmons provides a path toward significant optical nonlinearity, which is essential in quantum information processing and quantum networks. A large coupling strength requires nanometer-scale positioning accuracy of the emitter near the surface of the plasmonic structure, which is challenging. We demonstrate the coupling of single localized defects in a tungsten diselenide (WSe) monolayer self-aligned to the surface plasmon mode of a silver nanowire. The silver nanowire induces a strain gradient on the monolayer at the overlapping area, leading to the formation of localized defect emission sites that are intrinsically close to the surface plasmon. We measured an average coupling efficiency with a lower bound of 26% ± 11% from the emitter into the plasmonic mode of the silver nanowire. This technique offers a way to achieve efficient coupling between plasmonic structures and localized defects of two-dimensional semiconductors.

These authors contributed equally * Correspondence should be sent to E.W.: edowaks@umd.edu When an atom strongly couples to a cavity, it can undergo coherent vacuum Rabi oscillations.Controlling these oscillatory dynamics quickly relative to the vacuum Rabi frequency enables remarkable capabilities such as Fock state generation and deterministic synthesis of quantum states of light, as demonstrated using microwave frequency devices 1,2 . At optical frequencies, however, dynamical control of single-atom vacuum Rabi oscillations remains challenging. Here, we demonstrate coherent transfer of optical frequency excitation between a single quantum dot and a cavity by controlling vacuum Rabi oscillations. We utilize a photonic molecule 3-7 to simultaneously attain strong coupling and a cavity-enhanced AC Stark shift. The Stark shift modulates the detuning between the two systems on picosecond timescales, faster than the vacuum Rabi frequency. We demonstrate the ability to add and remove excitation from the cavity, and perform coherent control of light-matter states. These results enable ultra-fast control of atom-cavity interactions in a nanophotonic device platform.Much of the prior work investigating atomic systems strongly coupled to optical cavities has operated in the static regime. In this regime the coupling between the two systems remains constant and 2 the signature of strong coupling is observed either in the frequency domain in the form of vacuum Rabi splitting [8][9][10][11] , or by direct time-domain observation of vacuum Rabi oscillations 12 . Recently, there has been significant experimental progress in optically controlling the dynamical response of atomic systems strongly coupled to cavities for applications such as optical switching [13][14][15][16] , reversible storage of photonic qubits 17,18 , and hybrid quantum information processing 19,20 . These works have all operated in the adiabatic regime where the duration of the optical control pulse was long compared to the vacuum Rabi frequency.When the interaction between the atom and cavity is modulated fast compared the vacuum Rabi frequency, the system undergoes diabatic rapid passage. In this regime it becomes possible to coherently transfer energy between an atomic excitation and a cavity photon by directly controlling vacuum Rabi oscillations. This coherent transfer has been effectively implemented at microwave frequencies and has enabled capabilities such as Fock state generation 1 and synthesis of arbitrary photonic wavefunctions 2 . At optical frequencies, however, diabatic control of vacuum Rabi oscillations between a single atomic system and a cavity remains difficult.In this letter we report a demonstration of controlled transfer of excitation between a semiconductor quantum dot and a strongly coupled optical cavity by directly controlling vacuum Rabi oscillations diabatically. We use a pulsed AC Stark shift to control the detuning between the quantum dot and cavity on picosecond timescales, enabling ultra-fast control of light-matter intera...