Trionic Optical Potential for Electrons in Semiconductors

Laser-induced optical potentials for atoms have led to remarkable advances in precision measurement, quantum information, and towards addressing fundamental questions in condensed matter physics. Here, we describe analogous optical potentials for electrons in quantum wells and wires that can be generated by optically driving the transition between a single electron and a three-body electron-exciton bound state, known as a trion. The existence of a bound trion state adds a term to the ac Stark shift of the material proportional to the light intensity at the position of the electron. According to our theoretical calculations, this shift can be large relative to the thermal equilibrium temperature of the electron, resulting in a relatively strong optical potential that could be used to trap, guide, and manipulate individual electrons within a semiconductor quantum well or wire. These potentials can be thought of as artificial nano-structures on the scale of 100 nm that can be spin-dependent and reconfigurable in real-time. Our results suggest the possibility of integrating ultrafast optics and gate voltages in new resolved-carrier semiconductor opto-electronic devices, with potential applications in fields such as nano-electronics, spintronics, and quantum information processingComment: Article and Supplemental Materials; This is a preprint of the original submission to Nature Physic

Does diet affect breast cancer risk?

The role of specific dietary factors in breast cancer causation is not completely resolved. Results from prospective studies do not support the concept that fat intake in middle life has a major relation to breast cancer risk. However, weight gain in middle life contributes substantially to breast cancer risk. Alcohol is the best established dietary risk factor, probably by increasing endogenous estrogen levels. Hypotheses relating diet during youth to risk decades later will be difficult to test. Nevertheless, available evidence is strong that breast cancer risk can be reduced by avoiding weight gain during adult years, and by limiting alcohol consumption

Current Research on Complementary and Alternative Medicine (CAM) in the Treatment of Anxiety Disorders: An Evidence-Based Review

Complementary and alternative medicine (CAM) encompasses a wide range of different nonmainstream therapies that have been increasingly used for treatment or adjunctive treatment of various ailments with anxiety/anxiety disorders being one of the commonly CAM (self)-medicated conditions. Thousands of published papers refer to use of CAM in various psychiatric disorders or in healthy or medically ill patients with mood or anxiety difficulties. In this chapter we focus specifically on clinically diagnosed (in line with the standard criteria) anxiety disorders and overview evidence of efficacy/safety of a range of CAM modalities: biologically based therapies (typically herbal preparations and less so nutraceuticals); manipulative and body-based therapies (acupuncture, aerobic exercise, massage, therapeutic touch, repetitive transcranial magnetic stimulation, balneotherapy, and others); mind-body therapies (yoga, Morita therapy, Tai Chi, reiki, Chinese cognitive therapy, religious and spiritual interventions, relaxation, mediation, and mindfulness-based interventions); and alternative medical systems (Ayurveda, homeopathy). We focus exclusively on randomized controlled trials and attempt to evaluate the existing body of evidence in the same manner that is applied to mainstream treatments