Understanding the Barriers to Mental Health Services from a Lesbian, Gay, Bisexual, Transgender and Queer (LGBTQ+) Homeless Perspective

Aim: There is a lack of research into the barriers that Lesbian, Gay, Bisexual, Transgender, Queer and Questioning (LGBTQ+) homeless people encounter when accessing mental health services, despite psychological distress being highly prevalent but service use remaining low. Unique mental health challenges are thought to exist, but in order to recognise needs and enable services to improve accessibility, service user perspectives must be recognised. This study aimed to address this by exploring the mental health needs of LGBTQ+ homeless adults, the role of services, the barriers that exist and improvements that could be made. Method: Semi-structured interviews were conducted with nine LGBTQ+ participants, who had experiences of past or present homelessness and self-identified mental health needs. Recruitment occurred via charities and social media. Thematic analysis was used to interpret the data. Results: The analysis revealed three main themes: (1) ‘Rejection of identity’ referred to experiences of LGBTQ+ discrimination which can impact wellbeing, and contribute to homelessness and a fear of sharing identity when seeking help, (2) ‘Homelessness can strip away personhood’ described the detrimental impact of homelessness, which can result in isolation and loneliness and exacerbate existing mental health difficulties, (3) ‘A lack of appropriate support’ highlighted some of the multi-faceted barriers to mental health services faced by this population. Conclusion: A range of mental health needs were identified in the research sample, including shame, hopelessness, low mood and a loss of self-worth. The role for services may include family interventions to address rejection, organisational work to reduce discrimination, and prevention of repeat homelessness through the provision of psychological support. A number of barriers were suggested, such as long waiting lists, limited awareness of services, and previous experiences of unhelpful interventions or being denied appropriate support. Services may increase flexibility in the type and delivery of intervention, address discrimination in practice, improve inclusivity and better account for social issues. The implications for recovery and prevention policy and future research have been discussed

Temperature Measurement and Phonon Number Statistics of a Nanoelectromechanical Resonator

Measuring thermodynamic quantities can be easy or not, depending on the system that is being studied. For a macroscopic object, measuring temperatures can be as simple as measuring how much a column of mercury rises when in contact with the object. At the small scale of quantum electromechanical systems, such simple methods are not available and invariably detection processes disturb the system state. Here we propose a method for measuring the temperature on a suspended semiconductor membrane clamped at both ends. In this method, the membrane is mediating a capacitive coupling between two transmission line resonators (TLR). The first TLR has a strong dispersion, that is, its decaying rate is larger than its drive, and its role is to pump in a pulsed way the interaction between the membrane and the second TLR. By averaging the pulsed measurements of the quadrature of the second TLR we show how the temperature of the membrane can be determined. Moreover the statistical description of the state of the membrane, which is directly accessed in this approach is significantly improved by the addition of a Josephson Junction coupled to the second TLR.Comment: 9 pages, 5 figures. To appear in New Journal of Physic

Capacitive Coupling of Two Transmission Line Resonators Mediated by the Phonon Number of a Nanoelectromechanical Oscillator

Detection of quantum features in mechanical systems at the nanoscale constitutes a challenging task, given the weak interaction with other elements and the available technics. Here we describe how the interaction between two monomodal transmission-line resonators (TLRs) mediated by vibrations of a nano-electromechanical oscillator can be described. This scheme is then employed for quantum non-demolition detection of the number of phonons in the nano-electromechanical oscillator through a direct current measurement in the output of one of the TLRs. For that to be possible an undepleted field inside one of the TLR works as a amplifier for the interaction between the mechanical resonator and the remaining TLR. We also show how how the non-classical nature of this system can be used for generation of tripartite entanglement and conditioned mechanical coherent superposition states, which may be further explored for detection processes.Comment: 6 pages, 5 figure

Single-photon optomechanics in the strong coupling regime

We give a theoretical description of a coherently driven opto-mechanical system with a single added photon. The photon source is modeled as a cavity which initially contains one photon and which is irreversibly coupled to the opto-mechanical system. We show that the probability for the additional photon to be emitted by the opto-mechanical cavity will exhibit oscillations under a Lorentzian envelope, when the driven interaction with the mechanical resonator is strong enough. Our scheme provides a feasible route towards quantum state transfer between optical photons and micromechanical resonators.Comment: 14 pages, 6 figure

Quantum Dynamics of Three Coupled Atomic Bose-Einstein Condensates

The simplest model of three coupled Bose-Einstein Condensates (BEC) is investigated using a group theoretical method. The stationary solutions are determined using the SU(3) group under the mean field approximation. This semiclassical analysis using the system symmetries shows a transition in the dynamics of the system from self trapping to delocalization at a critical value for the coupling between the condensates. The global dynamics are investigated by examination of the stable points and our analysis shows the structure of the stable points depends on the ratio of the condensate coupling to the particle-particle interaction, undergoes bifurcations as this ratio is varied. This semiclassical model is compared to a full quantum treatment, which also displays the dynamical transition. The quantum case has collapse and revival sequences superposed on the semiclassical dynamics reflecting the underlying discreteness of the spectrum. Non-zero circular current states are also demonstrated as one of the higher dimensional effects displayed in this system.Comment: Accepted to PR

Wigner Function Evolution of Quantum States in Presence of Self-Kerr Interaction

A Fokker-Planck equation for the Wigner function evolution in a noisy Kerr medium ($\chi^{(3)}$ non-linearity) is presented. We numerically solved this equation taking a coherent state as an initial condition. The dissipation effects are discussed. We provide examples of quantum interference, sub-Planck phase space structures, and Gaussian versus non-Gaussian dynamical evolution of the state. The results also apply to the description of a nanomechanical resonator with an intrinsic Duffing nonlinearity.Comment: 10 pages, 11 figure

State reduction in quantum-counting quantum nondemolition measurements

We show how quantum-counting quantum nondemolition measurements may be made using standard demolition counting techniques (e.g., photoelectron counting) for two oscillators coupled via a four-wave-mixing interaction. The analysis reveals how the state of one oscillator is reduced to a number eigenstate during the irreversible demolition counting process occurring in another coupled oscillator

Standard Quantum Limits for broadband position measurement

I utilize the Caves-Milburn model for continuous position measurements to formulate a broadband version of the Standard Quantum Limit (SQL) for monitoring the position of a free mass, and illustrate the use of Kalman filtering to recover the SQL for estimating a weak classical force that acts on a quantum-mechanical test particle under continuous observation. These derivations are intended to clarify the interpretation of SQL's in the context of continuous quantum measurement.Comment: Replaced version: changed title, fixed algebra error at the very end, conclusions modified accordingly. Four pages, one eps figur

Analytic Approximation of the Tavis-Cummings Ground State via Projected States

We show that an excellent approximation to the exact quantum solution of the ground state of the Tavis-Cummings model is obtained by means of a semi-classical projected state. This state has an analytical form in terms of the model parameters and, in contrast to the exact quantum state, it allows for an analytical calculation of the expectation values of field and matter observables, entanglement entropy between field and matter, squeezing parameter, and population probability distributions. The fidelity between this projected state and the exact quantum ground state is very close to 1, except for the region of classical phase transitions. We compare the analytical results with those of the exact solution obtained through the direct Hamiltonian diagonalization as a function of the atomic separation energy and the matter-field coupling.Comment: 22 pages, 13 figures, accepted for publication in Physics Script