Physica Scripta is published by the IOP on behalf of the Royal Swedish Academy of Sciences for the Science Academies and the Physical Societies of the Nordic Countries.
Paper of the Week – Dark resonances from optical pumping to cold atoms and molecules Claude Cohen-Tannoudji reviews the various developments that have occurred in the field of dark resonances and dark states, putting an emphasis on the interpretation of the physical phenomena. He concludes that dark resonances continue to play an important role in the most recent developments of atomic and molecular physics, like nonlinear optics or ultracold quantum gases. This paper is part of the Focus Issue on Quantum Optics in the International Year of Light.
CEWQO 2015 Poster Prize Winner Physica Scripta is proud to have sponsored the Best Poster Prize at the 22nd Central European Workshop on Quantum Optics, 6-10 July 2015, Warsaw, Poland. The winners were Evgeny Kiktenko, PhD Student of the Bauman Technical University in Moscow and Jiri Maryska from Czech Technical University in Prague.
New collection of invited papers - Cold matter, quantum optics, and quantum information in Mexico
Physica Scripta is pleased to present this collection of 19 invited articles, which have been specially comissioned by Octavio Castanos and Margarita Man'ko of the Editorial Board
New special issue - 150 years of Margarita and Vladimir Man'ko
This special issue celebrates jubilees of two outstanding physicists and science organizers: Margarita Alexandrovna Man'ko and Vladimir Ivanovich Man'ko. The subjects of the papers cover rather wide areas of theoretical, mathematical and experimental physics.
New focus issues
Physica Scripta is pleased to present the first papers published in our newest focus issues: Focus on plasmas and nonlinear science: Symposium for Lennart Stenflo, Focus Issue on gravity, supergravity and fundamental physics: the Richard Arnowitt Symposium and Focus issue on Quantum Optics in the International Year of Light. More papers will be added to these issues over the coming months.
Highlights of 2014
Don't miss our new collection of papers, celebrating the research that was published with us last year. All the papers are free to read until 31 December 2015.
In the last 30 days
Kaj Sotala and Roman V Yampolskiy 2015 Phys. Scr. 90 018001
Many researchers have argued that humanity will create artificial general intelligence (AGI) within the next twenty to one hundred years. It has been suggested that AGI may inflict serious damage to human well-being on a global scale (‘catastrophic risk’). After summarizing the arguments for why AGI may pose such a risk, we review the fieldʼs proposed responses to AGI risk. We consider societal proposals, proposals for external constraints on AGI behaviors and proposals for creating AGIs that are safe due to their internal design.
V V Dodonov and A V Dodonov 2015 Phys. Scr. 90 074049
We give a short review of known exact inequalities that can be interpreted as ‘energy–time’ and ‘frequency–time’ uncertainty relations. In particular we discuss a precise form of signals minimizing the physical frequency–time uncertainty product. Also, we calculate the ‘stationarity time’ for mixed Gaussian states of a quantum harmonic oscillator, showing explicitly that pure quantum states are ‘more fragile’ than mixed ones with the same value of the energy dispersion. The problems of quantum evolution speed limits, time operators and measurements of energy and time are briefly discussed, too.
Victor Dodonov 2015 Phys. Scr. 90 070301
María A H Vozmediano and F Guinea 2012 Phys. Scr. 2012 014015
We give an update of the situation concerning the effect of electron–electron interactions on the physics of a neutral graphene system at low energies. We revise old renormalization group results and the use of 1/ N expansion to address questions of the possible opening of a low-energy gap, and the magnitude of the graphene fine structure constant. We emphasize the role of Fermi velocity as the only free parameter determining the transport and electronic properties of the graphene system and revise its renormalization by Coulomb interactions in the light of recent experimental evidence.
Carlo Gatti 2013 Phys. Scr. 87 048102
Narrating my scientific career, I show in this paper how, starting as a computational and theoretical chemist, I got naturally involved with x-ray crystallographers because of the common interest in charge density and in the study of chemical bonds based on such an observable. The tools I devised and the conceptual developments I made to facilitate a profitable encounter between x-ray charge density and computational chemistry researchers are illustrated, with a special focus on the proposal and applications of the Source Function concept.
Martin J Field and Troy W Wymore 2014 Phys. Scr. 89 108004
The 2013 Nobel Prize in Chemistry was awarded for the development of multiscale models for complex chemical systems, whereas the 2013 Peace Prize was given to the Organisation for the Prohibition of Chemical Weapons for their efforts to eliminate chemical warfare agents. This review relates the two by introducing the field of multiscale modeling and highlighting its application to the study of the biological mechanisms by which selected chemical weapon agents exert their effects at an atomic level.
B Cameron Reed 2015 Phys. Scr. 90 088001
August 2015 marks the 70th anniversary of the atomic bombings of Hiroshima and Nagasaki. These bombs, the products of the United States Army’s Manhattan Project, helped to end World War II and had enormous long-term effects on global political strategies by setting the stage for the Cold War and nuclear proliferation. This article explores the context and legacy of the Manhattan Project. The state of the war in the summer of 1945 is described, as are how the target cities came to be chosen, deliberations surrounding whether the bombs should be used directly or demonstrated first, and the long-term effects of the Project on individual scientists, the relationship between scientists and society, the subsequent development of nuclear arsenals around the world, and the current status of these arsenals and how they might evolve in the future.
D J Dunstan and D J Hodgson 2014 Phys. Scr. 89 068002
Many gardeners and horticulturalists seek non-chemical methods to control populations of snails. It has frequently been reported that snails that are marked and removed from a garden are later found in the garden again. This phenomenon is often cited as evidence for a homing instinct. We report a systematic study of the snail population in a small suburban garden, in which large numbers of snails were marked and removed over a period of about 6 months. While many returned, inferring a homing instinct from this evidence requires statistical modelling. Monte Carlo techniques demonstrate that movements of snails are better explained by drift under the influence of a homing instinct than by random diffusion. Maximum likelihood techniques infer the existence of two groups of snails in the garden: members of a larger population that show little affinity to the garden itself, and core members of a local garden population that regularly return to their home if removed. The data are strongly suggestive of a homing instinct, but also reveal that snail-throwing can work as a pest management strategy.
Gerd Leuchs et al 2015 Phys. Scr. 90 074066
We show that the different values 1, 2 and 3 of the normalized second-order correlation function corresponding to a coherent state, a thermal state and a highly squeezed vacuum originate from the different dimensionality of these states in phase space. In particular, we derive an exact expression for in terms of the ratio of the moments of the classical energy evaluated with the Wigner function of the quantum state of interest and corrections proportional to the reciprocal of powers of the average number of photons. In this way we establish a direct link between and the shape of the state in phase space. Moreover, we illuminate this connection by demonstrating that in the semi-classical limit the familiar photon statistics of a thermal state arise from an area in phase space weighted by a two-dimensional Gaussian, whereas those of a highly squeezed state are governed by a line-integral of a one-dimensional Gaussian.
S Pfalzner et al 2015 Phys. Scr. 90 068001
The solar system started to form about 4.56 Gyr ago and despite the long intervening time span, there still exist several clues about its formation. The three major sources for this information are meteorites, the present solar system structure and the planet-forming systems around young stars. In this introduction we give an overview of the current understanding of the solar system formation from all these different research fields. This includes the question of the lifetime of the solar protoplanetary disc, the different stages of planet formation, their duration, and their relative importance. We consider whether meteorite evidence and observations of protoplanetary discs point in the same direction. This will tell us whether our solar system had a typical formation history or an exceptional one. There are also many indications that the solar system formed as part of a star cluster. Here we examine the types of cluster the Sun could have formed in, especially whether its stellar density was at any stage high enough to influence the properties of today’s solar system. The likelihood of identifying siblings of the Sun is discussed. Finally, the possible dynamical evolution of the solar system since its formation and its future are considered.