Exact propagation of open quantum systems in a system-reservoir context

A stochastic representation of the dynamics of open quantum systems, suitable for non-perturbative system-reservoir interaction, non-Markovian effects and arbitrarily driven systems is presented. It includes the case of driving on timescales comparable to or shorter than the reservoir correlation time, a notoriously difficult but relevant case in the context of quantum information processing and quantum thermodynamics. A previous stochastic approach is re-formulated for the case of finite reservoir correlation and response times, resulting in a numerical simulation strategy exceeding previous ones by orders of magnitude in efficiency. Although the approach is based on a memory formalism, the dynamical equations propagated in the simulations are time-local. This leaves a wide range of choices in selecting the system to be studied and the numerical method used for propagation. For a series of tests, the dynamics of the spin-boson system is computed in various settings including strong external driving and Landau-Zener transitions.Comment: 7 pages, 4 figures. v2: inset in Fig. 2 and some text added, further references. v3: minor correction

Simulating spin-boson dynamics with stochastic Liouville-von Neumann equations

Based on recently derived exact stochastic Liouville-von Neumann equations, several strategies for the efficient simulation of open quantum systems are developed and tested on the spin-boson model. The accuracy and efficiency of these simulations is verified for several test cases including both coherent and incoherent dynamics, involving timescales differing by several orders of magnitude. Using simulations with a time-dependent field, the time evolution of coherences in the reduced density matrix is investigated. Even in the case of weak damping, pronounced preparation effects are found. These indicate hidden coherence in the interacting system which can only be indirectly observed in the basis of the reduced quantum dynamics.Comment: 25 pages, 7 figures; to be published in Chemical Physic

The Integration of TBRI & Expressive Therapies Continuum: In-Home Expressive Arts Interventions for Foster and Adoptive Families During COVID-19

With the onset of COVID-19 and the necessary isolation of a global pandemic, the therapeutic space was forced to redefine itself within the virtual realm as the ripple effect of collective trauma further compounded families healing from complex or relational trauma. Clinicians were virtually invited more into participants’ living spaces and interdependence with interpersonal family dynamics through this evolution. By combing the evidence-based practice of Trust-Based Relational Interventions with the framework of the Expressive Therapies Continuum, a more expansive, embodied, and uniquely client-centered, neurologically developmental approach emerged that engaged the healing potential of the caregiver-child relationship through increased co-regulation and attachment creating a connective bridge between the therapeutic space and participant’s homes while offering stability to adjusting daily family rhythms. Arts-based exploration was conducted through a collection of in-home expressive arts interventions formatted as a COVID-19 blog resource response for foster and adoptive families. Utilizing easily resourced materials and engagement of dyadic relationships, the interventions sought to meet participants where they were mentally, emotionally, and physically within daily rituals, creating pockets or ‘cocoons’ of healing connection. Results through triadic qualitative measurements revealed themes of increased experience of co-regulation and attunement, fostered non-verbal awareness, increased desire for connection, and pathways for expression of difficult emotions offering opportunities validation through both witnessing and empathetic listening. Further, a virtual space was offered for families’ individual artistic expressions of relationship to be shared creating a diverse sense of community, a defiant hope in the isolation of social distancing, to both clinicians and participants alike that fostered compassionate scaffolding; the ancient wisdom of the expressive arts offering movement in a global pause

Breaking Peroxy Bonds in H20 Ice Doped with H202 to Create Positive Hole Charge Carriers.

Using stress-activated electric conductivity in water ice doped with hydrogen peroxide as a model for stress-activated electric conductivity of igneous and high-grade metamorphic rocks due to the presence of peroxy defects, which when broken, createpositive-hole charge carriers. Blocks of pure H2O ice and H2O2–doped H2O ices, frozen at –20°C, will be stressed with piezo electric transducers(pzt) at one end to generate stress-activated electric currents flowing down the stress gradient. Pure H2O ice should produce no current or a small insignificant amount during rapid deformation or fracture. Stressing H2O2-doped H2O ices, however, should lead to 100-1000 times higher currents. These stress-activated currents are carried by defect electrons, generated by the break-up of the peroxy bonds of H2O2molecules embedded in the ice structure. These defect electrons are associated with the oxygen anion sub-lattice and known as positive holes. H2O2–doped H2O ices can be viewed as analogs to igneous and high-grade metamorphic rocks, which naturally contain peroxy defects, typically O3Si-OO-SiO3, and also produce positive hole currents when subjected to stres