Entangling a nanomechanical resonator with a microwave field

We show how the coherent oscillations of a nanomechanical resonator can be entangled with a microwave cavity in the form of a superconducting coplanar resonator. Dissipation is included and realistic values for experimental parameters are estimated.Comment: submitted to J. Mod. Op

Laser phase noise effects on the dynamics of optomechanical resonators

We investigate theoretically the influence of laser phase noise on the cooling and heating of a generic cavity optomechanical system. We derive the back-action damping and heating rates and the mechanical frequency shift of the radiation pressure-driven oscillating mirror, and derive the minimum phonon occupation number for small laser linewidths. We find that in practice laser phase noise does not pose serious limitations to ground state cooling. We then consider the effects of laser phase noise in a parametric cavity driving scheme that minimizes the back-action heating of one of the quadratures of the mechanical oscillator motion. Laser linewidths narrow compared to the decay rate of the cavity field will not pose any problems in an experimental setting, but broader linewidths limit the practicality of this back-action evasion method.Comment: 9 pages, 7 figure

Making sense of eating, weight and risk in the early teenage years: views and concerns of parents in poorer socio-economic circumstances

Peer reviewe

A degenerate three-level laser with a parametric amplifier

The aim of this paper is to study the squeezing and statistical properties of the light produced by a degenerate three-level laser whose cavity contains a degenerate parametric amplifier. In this quantum optical system the top and bottom levels of the three-level atoms injected into the laser cavity are coupled by the pump mode emerging from the parametric amplifier. For a linear gain coefficient of 100 and for a cavity damping constant of 0.8, the maximum intracavity squeezing is found at steady state and at threshold to be 93%.Comment: 8 pages, 4 figures, published versio

Following the Flâneur: a Methodological and Textual Critique

This paper resulted from a workshop entitled ‘Writing Cities’, which took place at the University of Nottingham on 9th June 2009. A methodological critique, it traces the evolution of the flâneur and examines the distinctive ways of seeing and writing associated with that figure. The paper draws connections between material alterations to the fabric of the city and the cultural formations that result from them. In this context, it recognises that the building of the Parisian arcades was a necessary material determinant of the advent of flânerie. Additionally, the paper sketches a family tree of flânerie, one that branches out beyond the familiar confines of French literature. Antecedents of the flâneur are discovered in the work of DeQuincey and Poe, whilst its descendants are encountered in later metropolitan settings, particularly in mediated representations of the mid-twentieth century American city. In relation to the latter focal point, a comparison is made between the Private Investigator – and the ways in which he inhabits his nourish, urban milieu – and the original flâneur, in nineteenth century Paris. An assertion is made that both of these city archetypes embraced a distanced perspective and adopted a ‘totalizing’ – but also profoundly selective – gaze in their differing attempts to reveal and apprehend the metropolis

Futurism and Musical Meaning in Synthesized Landscapes

The purpose of this paper is to explore how musicians engaged with a particular form of technology, the synthesizer, to create imaginative geographies of the near future. It examines the output of numerous ‘synth-pop’ acts involved in the production of this commercially successful, urban-focussed music, focussing on the period between 1977 and 1984. Attention is given to how this music both embedded and self-consciously reflected notions of futurism, a theme that, until that time, had largely been neglected in popular music. The role of earlier futuristic visionaries, such as Fritz Lang, JG Ballard and Stanley Kubrick, in shaping musicians depictions of futurism is highlighted. Throughout, the music is interpreted by situating it within the specific cultural, economic and socio-technical realms in which it was produced. Whilst the emphasis is on debates concerning futurism that were played out within a British musical context reference is also made to related significant developments that occurred outside the UK

Delhi Durbar Dress. In Derbyshire.

This is a blog post I wrote in connection with work I undertook as a Historical Geography Research Fellow, whilst based at the University of Exeter. In this capacity, I worked on a project, led by Dr Nicola Thomas, which critically investigated different geographies pertaining to Lady Mary Curzon, Vicereine of India from 1899 to 1905. This AHRC funded work, administered as a REACT Sandbox books and print scheme, sought to develop new ways of increasing the visibility of academic work. It did this, in part, by probing how such research could connect to new audiences via the incorporation of new media technologies. As such, SpinMe photography was utilised in the project and a dedicated prototype Android app about Lady Curzon was developed. Later, in 2019, a Channel Five programme was broadcast that explored the significance of, and the ongoing interest in, the subject of this blog post: the Peacock Dress – a remarkably storied piece of clothing, but which was only ever worn once, at the 1903 Delhi Durbar State Ball

Comment on "Evidence for Quantized Displacement in Macroscopic Nanomechanical Oscillators"

In a recent Letter, Gaidarzhy et al. [1] claim to have observed evidence for "quantized displacements" of a high-order mode of a nanomechanical oscillator. We contend that the methods employed by the authors are unsuitable in principle to observe such states for any harmonic mode

Intracavity weak nonlinear phase shifts with single photon driving

We investigate a doubly resonant optical cavity containing a Kerr nonlinear medium that couples two modes by a cross phase modulation. One of these modes is driven by a single photon pulsed field, and the other mode is driven by a coherent state. We find an intrinsic phase noise mechanism for the cross phase shift on the coherent beam which can be attributed to the random emission times of single photons from the cavity. An application to a weak nonlinearity phase gate is discussed

Ion trap transducers for quantum electromechanical oscillators

An enduring challenge for contemporary physics is to experimentally observe and control quantum behavior in macroscopic systems. We show that a single trapped atomic ion could be used to probe the quantum nature of a mesoscopic mechanical oscillator precooled to 4K, and furthermore, to cool the oscillator with high efficiency to its quantum ground state. The proposed experiment could be performed using currently available technology.Comment: 4 pages, 2 figure