Research Repository

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Dynamical multistability in a quantum dot laser (2019)
Journal Article
Mantovani, M., Armour, A. D., Belzig, W., & Rastelli, G. (2019). Dynamical multistability in a quantum dot laser. Physical Review B, 99(4), doi:10.1103/PhysRevB.99.045442

We study the dynamical multistability of a solid-state single-atom laser implemented in a quantum dot spin valve. The system is formed by a resonator that interacts with a two-level system in a dot in contact with two ferromagnetic leads of antiparal... Read More

Noise switching at a dynamical critical point in a cavity-conductor hybrid (2017)
Journal Article
Armour, A. D., Kubala, B., & Ankerhold, J. (in press). Noise switching at a dynamical critical point in a cavity-conductor hybrid. Physical Review B, 96(21), doi:10.1103/PhysRevB.96.214509. ISSN 2469-9950

Coupling a mesoscopic conductor to a microwave cavity can lead to fascinating feedback effects which generate strong correlations between the dynamics of photons and charges. We explore the connection between cavity dynamics and charge transport in... Read More

Quantum dynamics of a Josephson junction driven cavity mode system in the presence of voltage bias noise (2017)
Journal Article
Wang, H., Blencowe, M., Armour, A., & Rimberg, A. (2017). Quantum dynamics of a Josephson junction driven cavity mode system in the presence of voltage bias noise. Physical Review B, 96(10), doi:10.1103/PhysRevB.96.104503. ISSN 2469-9950

We give a semiclassical analysis of the average photon number as well as photon number variance (Fano factor F) for a Josephson junction (JJ) embedded microwave cavity system, where the JJ is subject to a fluctuating (i.e., noisy) bias voltage with f... Read More

Spin correlations as a probe of quantum synchronization in trapped ion phonon-lasers (2015)
Journal Article
Hush, M. R., Li, W., Genway, S., Lesanovsky, I., & Armour, A. (2015). Spin correlations as a probe of quantum synchronization in trapped ion phonon-lasers. Physical Review A, 91, doi:10.1103/PhysRevA.91.061401. ISSN 2469-9926

We investigate quantum synchronization theoretically in a system consisting of two cold ions in microtraps. The ions' motion is damped by a standing-wave laser whilst also being driven by a blue-detuned laser which results in self-oscillation. Workin... Read More

Josephson photonics with a two-mode superconducting circuit (2015)
Journal Article
Armour, A. D., Kubala, B., & Ankerhold, J. (2015). Josephson photonics with a two-mode superconducting circuit. Physical Review B, 91(184508), doi:10.1103/PhysRevB.91.184508. ISSN 2469-9950

We analyze the quantum dynamics of two electromagnetic oscillators coupled in series to a voltage-biased Josephson junction. When the applied voltage leads to a Josephson frequency across the junction which matches the sum of the two mode frequencies... Read More

Realization of a single-Cooper-pair Josephson laser (2014)
Journal Article
Chen, F., Li, J., Armour, A., Brahimi, E., Stettenheim, J., Sirois, A., …Rimberg, A. (2014). Realization of a single-Cooper-pair Josephson laser. Physical Review B, 90, doi:10.1103/PhysRevB.90.020506. ISSN 2469-9950

We have embedded a voltage-biased Cooper-pair transistor (CPT) in a high-Q superconducting microwave cavity. When the energy given to a tunneling Cooper pair by the voltage bias is equal to a multiple of the cavity photon frequency, the cavity is pum... Read More

A cavity-Cooper pair transistor scheme for investigating quantum optomechanics in the ultrastrong coupling regime (2014)
Journal Article
Rimberg, A., Blencowe, M., Armour, A., & Nation, P. (2014). A cavity-Cooper pair transistor scheme for investigating quantum optomechanics in the ultrastrong coupling regime. New Journal of Physics, 16, doi:10.1088/1367-2630/16/5/055008. ISSN 1367-2630

We propose a scheme involving a Cooper pair transistor (CPT) embedded in a superconducting microwave cavity, where the CPT serves as a charge tunable quantum inductor to facilitate ultra-strong coupling between photons in the cavity and a nano- to me... Read More

Nonlinear modal coupling in a high-stress doubly-clamped nanomechanical resonator (2012)
Journal Article
Lulla, K., Cousins, R., Venkatesan, A., Patton, M., Armour, A., Mellor, C. J., & Owers-Bradley, J. (2012). Nonlinear modal coupling in a high-stress doubly-clamped nanomechanical resonator. New Journal of Physics, 14, doi:10.1088/1367-2630/14/11/113040. ISSN 1367-2630

We present results from a study of the nonlinear inter-modal coupling between different flexural vibrational modes of a single high-stress, doubly-clamped silicon nitride nanomechanical beam. Using the magnetomotive technique and working at 100 mK we... Read More