All Outputs (14)

Reflection by two level system: phase singularities on the Poincaré hypersphere (2023)
Journal Article
Lang, B., Harbord, E., & Oulton, R. (2023). Reflection by two level system: phase singularities on the Poincaré hypersphere. Journal of Optics, 25(12), Article 125403. https://doi.org/10.1088/2040-8986/ad065a

We consider the reflection of a photon by a two-level system in a quasi-one-dimensional waveguide. The waveguide polarisation at the location of the two-level system and the transition dipole are key determinants of the physics, controlling of the ph... Read More about Reflection by two level system: phase singularities on the Poincaré hypersphere.

Discrete time translation symmetry breaking in a Josephson junction laser (2023)
Journal Article
Lang, B., Morley, G. F., & Armour, A. D. (2023). Discrete time translation symmetry breaking in a Josephson junction laser. Physical review B: Condensed matter and materials physics, 107(14), Article 144509. https://doi.org/10.1103/PhysRevB.107.144509

A Josephson junction laser is realized when a microwave cavity is driven by a voltage-biased Josephson junction. Through the ac Josephson effect, a dc voltage generates a periodic drive that acts on the cavity and generates interactions between its m... Read More about Discrete time translation symmetry breaking in a Josephson junction laser.

Witnessing Bell violations through probabilistic negativity (2022)
Journal Article
Morris, B., Fiderer, L. J., Lang, B., & Goldwater, D. (2022). Witnessing Bell violations through probabilistic negativity. Physical Review A, 105(3), Article 032202. https://doi.org/10.1103/physreva.105.032202

Bell's theorem shows that no local hidden-variable model can explain the measurement statistics of a quantum system shared between two parties, thus ruling out a classical (local) understanding of nature. In this paper we demonstrate that by relaxing... Read More about Witnessing Bell violations through probabilistic negativity.

Perfect Chirality with Imperfect Polarization (2022)
Journal Article
Lang, B., McCutcheon, D. P., Harbord, E., Young, A. B., & Oulton, R. (2022). Perfect Chirality with Imperfect Polarization. Physical Review Letters, 128(7), Article 073602. https://doi.org/10.1103/physrevlett.128.073602

Unidirectional (chiral) emission of light from a circular dipole emitter into a waveguide is only possible at points of perfect circular polarization (C points), with elliptical polarizations yielding a lower directional contrast. However, there is n... Read More about Perfect Chirality with Imperfect Polarization.

Josephson photonics with simultaneous resonances (2021)
Journal Article
Wood, K., Armour, A. D., & Lang, B. (2021). Josephson photonics with simultaneous resonances. Physical Review B, 104(15), Article 155424. https://doi.org/10.1103/physrevb.104.155424

Inelastic Cooper pair tunneling across a voltage-biased Josephson junction in series with one or more microwave cavities can generate photons via resonant processes in which the energy lost by the Cooper pair matches that of the photon(s) produced. W... Read More about Josephson photonics with simultaneous resonances.

Multi-Photon Resonances in Josephson Junction-Cavity Circuits (2021)
Journal Article
Lang, B., & Armour, A. (2021). Multi-Photon Resonances in Josephson Junction-Cavity Circuits. New Journal of Physics, 23(3), Article 033021. https://doi.org/10.1088/1367-2630/abe483

We explore the dissipative dynamics of nonlinearly driven oscillator systems tuned to resonances where multiple excitations are generated. Such systems are readily realised in circuit QED systems combining Josephson junctions with a microwave cavity... Read More about Multi-Photon Resonances in Josephson Junction-Cavity Circuits.

Collectively enhanced chiral photon emission from an atomic array near a nanofiber (2020)
Journal Article
Jones, R., Buonaiuto, G., Lang, B., Lesanovsky, I., & Olmos, B. (2020). Collectively enhanced chiral photon emission from an atomic array near a nanofiber. Physical Review Letters, 124(9), Article 093601. https://doi.org/10.1103/physrevlett.124.093601

Emitter ensembles interact collectively with the radiation field. In the case of a one-dimensional array of atoms near a nanofiber, this collective light-matter interaction does not only lead to an increased photon coupling to the guided modes within... Read More about Collectively enhanced chiral photon emission from an atomic array near a nanofiber.

99% beta factor and directional coupling of quantum dots to fast light in photonic crystal waveguides determined by spectral imaging (2019)
Journal Article
Scarpelli, L., Lang, B., Masia, F., Beggs, D. M., Muljarov, E. A., Young, A. B., …Langbein, W. (2019). 99% beta factor and directional coupling of quantum dots to fast light in photonic crystal waveguides determined by spectral imaging. Physical Review B, 100(3), Article 035311. https://doi.org/10.1103/PhysRevB.100.035311

© 2019 American Physical Society. Spontaneous emission from excitonic transitions in InAs/GaAs quantum dots embedded in photonic crystal waveguides at 5 K into nonguided and guided modes is determined by direct spectral imaging. This enables measurem... Read More about 99% beta factor and directional coupling of quantum dots to fast light in photonic crystal waveguides determined by spectral imaging.

Optimised photonic crystal waveguide for chiral light–matter interactions (2017)
Journal Article
Lang, B., Oulton, R., & Beggs, D. M. (2017). Optimised photonic crystal waveguide for chiral light–matter interactions. Journal of Optics, 19(4), Article 045001. https://doi.org/10.1088/2040-8986/aa5f5f

We present slow-light photonic crystal waveguide designs that provide a ×8.6 improvement of the local density of optical states at a fully chiral point over previous designs.

Time-reversal constraint limits unidirectional photon emission in slow-light photonic crystals (2016)
Journal Article
Lang, B., Beggs, D. M., & Oulton, R. (2016). Time-reversal constraint limits unidirectional photon emission in slow-light photonic crystals. Philosophical Transactions A: Mathematical, Physical and Engineering Sciences, 374(2075), https://doi.org/10.1098/rsta.2015.0263

Photonic crystal waveguides are known to support C-points—point-like polarization singularities with local chirality. Such points can couple with dipole-like emitters to produce highly directional emission, from which spin-photon entanglers can be bu... Read More about Time-reversal constraint limits unidirectional photon emission in slow-light photonic crystals.

Stability of polarization singularities in disordered photonic crystal waveguides (2015)
Journal Article
Lang, B., Beggs, D. M., Young, A. B., Rarity, J. G., & Oulton, R. (2015). Stability of polarization singularities in disordered photonic crystal waveguides. Physical Review A, 92(6), Article 063819. https://doi.org/10.1103/physreva.92.063819

The effects of short-range disorder on the polarization characteristics of light in photonic crystal waveguides were investigated using finite-difference time-domain simulations with a view to investigating the stability of polarization singularities... Read More about Stability of polarization singularities in disordered photonic crystal waveguides.

Closed sets of correlations: answers from the zoo (2014)
Journal Article
Lang, B., Vértesi, T., & Navascués, M. (2014). Closed sets of correlations: answers from the zoo. Journal of Physics A: Mathematical and Theoretical, 47(42), Article 424029. https://doi.org/10.1088/1751-8113/47/42/424029

We investigate the conditions under which a set of multipartite nonlocal correlations can describe the distributions achievable by distant parties conducting experiments in a consistent universe. Several questions are posed, such as: are all such set... Read More about Closed sets of correlations: answers from the zoo.

Modelling Photonic Crystal Surface Emitting Lasers (PCSELs) with Iterative Weighted Index Method
Presentation / Conference Contribution
Lang, B., Vukovic, A., Sewell, P., Rihani, S., Boylan, K., Berry, G., Hattasan, N., Moodie, D., & Rawsthorne, J. (2023, October). Modelling Photonic Crystal Surface Emitting Lasers (PCSELs) with Iterative Weighted Index Method. Presented at 2023 International Conference on Electromagnetics in Advanced Applications, ICEAA 2023, Venice, Italy

Photonic crystal surface emitting lasers (PCSELs) are a promising type of semiconductor laser, able to maintain single-mode operation over a large area, resulting in a high-power beam with small angular divergence.

Unstructured Transmission Line Modelling (TLM) Method for Modelling of Advanced Photonic Structures
Presentation / Conference Contribution
Vukovic, A., Sewell, P., Dimitrijevic, T., Lang, B., Rihani, S., Boylan, K., Berry, G., Hattasan, N., Moodie, D., Rawsthorne, J., & Robertson, M. (2023, October). Unstructured Transmission Line Modelling (TLM) Method for Modelling of Advanced Photonic Structures. Presented at 16th International Conference on Advanced Technologies, Systems and Services in Telecommunications (TELSIKS 2023)), Niš , Serbia

This paper overviews the most recent advances in the unstructured Transmission Line Modelling method that is uniquely placed for modeling advanced photonic applications with multi-scale features. The paper focuses on the holistic approach that needs... Read More about Unstructured Transmission Line Modelling (TLM) Method for Modelling of Advanced Photonic Structures.