Tunneling and Electric-Field Effects on Electron-Hole Localization in Artificial Molecules

We theoretically investigate the Stark shift of the exciton goundstate in two vertically coupled quantum dots as a function of the interdot distance. The coupling is shown to enhance the tuneability of the linear optical properties, including energy and oscillator strength, as well as the exciton polarizability. The coupling regime that maximizes these properties results from the detailed balance between the effects of the single-particle tunneling, of the electric field and of the carrier-carrier interaction. We discuss the relevance of these results to the possible implementation of quantum-information processing based on semiconductor quantum dots: in particular, we suggest the identification of the qubits with the exciton levels in coupled- rather than single-dots

Gaussian Mean Fields Lattice Gas

We study rigorously a lattice gas version of the Sherrington-Kirckpatrick spin glass model. In discrete optimization literature this problem is known as Unconstrained Binary Quadratic Programming (UBQP) and it belongs to the class NP-hard. We prove that the fluctuations of the ground state energy tend to vanish in the thermodynamic limit, and we give a lower bound of such ground state energy. Then we present an heuristic algorithm, based on a probabilistic cellular automaton, which seems to be able to find configurations with energy very close to the minimum, even for quite large instances.Comment: 3 figures, 2 table

Energy as witness of multipartite entanglement in spin clusters

We derive energy minima for biseparable states in three- and four-spin systems, with Heisenberg Hamiltonian and s <= 5/2. These provide lower bounds for tripartite and quadripartite entanglement in chains and rings with larger spin number N. We demonstrate that the ground state of an $N$-spin Heisenberg chain is $N$-partite entangled, and compute the energy gap with respect to biseparable states for N <= 8

The Elephant in the Room: How neoliberal architecture education undermines wellbeing

This essay examines the performative space of neoliberal architectural education in the United Kingdom, its history, attributes and values, focusing on staff and student wellbeing in relation to work-time. Here, it is argued that the unhealthy and imbalanced long work hours culture of the architectural design studio, which has been exacerbated under neoliberalism and post- pandemic through online studio teaching, needs to be acknowledged as ‘the elephant in the room’ of architectural education. As a workspace in which unhealthy work practices are acculturated, and consequently perpetuated from the university into the architect’s work life, the vertical unit system encourages a competitive ego culture at the expense of a balanced work life. In a neoliberal market economy, how might architectural design studio education be reframed to enhance wellbeing

Academic capitalism in architecture schools: A feminist critique of employability, 24/7 work and entrepreneurship

This chapter examines the current situation that many universities worldwide are facing due to globalisation, which is of transitioning from institutions for education (Foucault’s ‘premodern or medieval university’) to entrepreneurial businesses (the ‘modern university’). The modern university is governed by a neoliberal system of production and consumption of students, staff, knowledge and research for the purpose of improving nation economies. Looking particularly at schools of architecture, it discusses employability, 24-hour work and entrepreneurship in relation to marketisation and economisation. It tracks the inequalities that arise from the neoliberalisation of public universities on teaching content, an administrative-directed work, workloads, wellbeing and gender. The chapter argues that the shift to entrepreneurial architectural education needs to be challenged through a ‘feminist politics for resistance’ (Mountz et al. 2015) so as to not undermine higher education. Those resistances should aim to actively challenge, at every opportunity, rather than acquiesce to ‘academic capitalism’

Detection of entanglement between collective spins

Entanglement between individual spins can be detected by using thermodynamics quantities as entanglement witnesses. This applies to collective spins also, provided that their internal degrees of freedom are frozen, as in the limit of weakly-coupled nanomagnets. Here, we extend such approach to the detection of entanglement between subsystems of a spin cluster, beyond such weak-coupling limit. The resulting inequalities are violated in spin clusters with different geometries, thus allowing the detection of zero- and finite-temperature entanglement. Under relevant and experimentally verifiable conditions, all the required expectation values can be traced back to correlation functions of individual spins, that are now made selectively available by four-dimensional inelastic neutron scattering