EPJ D Highlight  Highfidelity quantum secret sharing prevents eavesdropping
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 Published on Wednesday, 11 July 2018 09:00
Quantum secretsharing scheme for noisy environments
To protect the confidentiality of a message during its transmission, people encrypt it. However, noise in the transmission channels can be a source of concern regarding how faithful the message transmission may be after it has been decrypted. This is particularly important for secrets shared using quantum scale messengers. For example, a classical secret takes the shape of a string of zeros and ones, whereas a quantum secret is akin to an unknown quantum state of two entangled particles carrying the secret. This is because no two quantum particles can be in the same state at any given time. In a new study published in EPJ D, ChenMing Bai from Shaanxi Normal University, Xi’an, China, and colleagues calculate the degree of fidelity of the quantum secret once transmitted and explore how to avoid eavesdropping.
EPJ D Highlight  When photons spice up the energy levels of quantum particles
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 Published on Tuesday, 12 June 2018 13:50
New study reveals theoretical calculation of new possible state for quantum particles which have received a photon
Quantum particles behave in mysterious ways. They are governed by laws of physics designed to reflect what is happening at smaller scales through quantum mechanics. Quantum state properties are generally very different to those of classical states. However, particles finding themselves in a coherent state are in a kind of quantum state which behaves like a classical state. Since their introduction by Erwin Schrödinger in 1926, coherent states of particles have found many applications in mathematical physics and quantum optics.
Now, for the first time, a team of mathematical physicists from Togo and Benin, call upon supersymmetry  a subdiscipline of quantum mechanics  to explain the behaviour of particles that have received a photon. These particles are subjected to particular potential energies known as shapeinvariant potentials.
In a paper published in EPJ D, Komi Sodoga and colleagues affiliated with both the University of Lomé, Togo, and the University of AbomeyCalavi, in Cotonou, Benin, outline the details of their theory. These findings are relevant to scientists working on solving quantum optics and quantum mechanics applications.
EPJ D Colloquium  Experimental progress in positronium laser physics
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 Published on Tuesday, 15 May 2018 14:10
The field of experimental positronium physics has advanced significantly in the last few decades, with new areas of research driven by the development of techniques for trapping and manipulating positrons using Surkotype buffer gas traps. Large numbers of positrons (typically ≥106) accumulated in such a device may be ejected all at once, so as to generate an intense pulse.
EPJD Highlight  Antimatter study to benefit from recipe for tenfold spatial compression of plasma
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 Published on Thursday, 03 May 2018 10:58
Improving the spatial compression of a mixed matterantimatter trapped plasma brings us one step closer to grasping the acceleration of antimatter due to Earth’s gravity
An international team of physicists studying antimatter have now derived an improved way of spatially compressing a state of matter called nonneutral plasma, which is made up of a type of antimatter particles, called antiprotons, trapped together with matter particles, like electrons.
Topical Review  Theory of the n=2 levels in muonic helium3 ions
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 Published on Friday, 09 March 2018 09:06
In this new article in EPJ D, Franke et al. review the present understanding of Lamb shift, fine and hyperfine structure of the 2S and 2P states in muonic helium3 ions in anticipation of the results of the first measurements of several 2S > 2P transition frequencies in the muonic helium3 ion, 3He+. This ion is the bound state of a single negative muon μ and a bare helium3 nucleus (helion), 3He++.
EPJ D Highlight  Approximate quantum cloning: the new way of eavesdropping in quantum cryptography
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 Published on Friday, 16 February 2018 12:16
New approximate cloning method avoids the previous limitations of quantum cloning to enhance quantum computing and quantum cryptography leaks
Cloning of quantum states is used for eavesdropping in quantum cryptography. It also has applications in quantum computation based on quantum information distribution. Uncertainty at the quantum scale makes exact cloning of quantum states impossible. Yet, they may be copied in an approximate way  with a certain level of probability  using a method called probabilistic quantum cloning, or PQC. In a new study published in EPJ D, Pinshu Rui from Anhui Xinhua and Anhui Universities, based in Hefei, China, and colleagues demonstrate that partial PQC of a given quantum state secretly chosen from a certain set of states, which can be expressed as the superposition of the other states, is possible.
EPJ D Highlight  Quantum noise reduction method for enhanced precision in atomic clocks
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 Published on Thursday, 21 December 2017 19:56
Atomic Spin Squeezing: not the Olympic sport of your dreams, but a way of enhancing measurement reliability at the quantum scale
Noise: it affects us all by distracting us. Noise also occurs at the quantum scale and can e.g. interfere with the measurements of atomic fountain clocks or with quantum information processing. This is because at that scale, there are effects that don't exist at larger scales. As such, finding ways to reduce quantum noise can enhance the precision of measurement in the examples given above. Now a team of physicists including Aranya Bhattacherjee from Jawaharlal Nehru University, New Delhi, India and colleagues are investigating ways of improving the analysis of quantum noise measurement in the case of spectroscopic investigations; their preliminary findings were released in a study in EPJ D. This method, called atomic spin squeezing, works by redistributing the uncertainty unevenly between two components of spin in these measurements systems, which operate at the quantum scale. The spin represents a degree of freedom of the quantum particles involved. Thus, the spin component with reduced uncertainty becomes more precise in delivering its measurement  as the two are inversely correlated. Potential applications include the development of future quantum networks.
EPJ D Highlight  Droplet explosion by shock waves, relevant to nuclear medicine
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 Published on Wednesday, 22 November 2017 09:49
Ion beam cancer therapy could be improved if ioninduced shock waves are discovered. A new study explores how these predicted waves can be observed
An arrow shooting through an apple, makes for a spectacular explosive sight in slow motion. Similarly, energetic ions passing through liquid droplets induce shock waves, which can fragment the droplets. In a study published in EPJ D, Eugene Surdutovich from Oakland University, Rochester, Michigan, USA with his colleagues from the MBN Research Centre, Frankfurt, Germany have proposed a solution to observe the predicted ioninduced shock waves. They believe these can be identified by observing the way incoming ions fragment liquid droplets into multiple smaller droplets. The discovery of such shock waves would change our understanding of the nature of radiation damage with ions to cancerous tumour. This matters for the optimisation of ionbeam cancer therapy, which requires a thorough understanding of the relation between the physical characteristics of the incoming ion beam and its effects on biological tissues.
EPJ D Colloquium  Twodimensional laserinduced fluorescence in the gas phase: a spectroscopic tool for studying molecular spectroscopy and dynamics
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 Published on Thursday, 16 November 2017 14:49
Twodimensional laserinduced fluorescence (2DLIF) extends the usual laserinduced fluorescence technique by incorporating a second dimension, namely the wavelengths at which the excited molecules emit, thereby significantly enhancing the information that can be extracted. It allows overlapping absorption features, whether they arise from within the same molecule or from different molecules in a mixture, to be associated with their appropriate "parent" state and/or molecule.
EPJ D Highlight  Quantum manipulation power for quantum information processing gets a boost
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 Published on Tuesday, 26 September 2017 22:08
Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power
Traditionally, heat engines produce heat from the exchange between hightemperature and lowtemperature baths. Now, imagine a heat engine that operates at quantum scale, and a system made up of an atom interacting with light (photons) confined in a reflective cavity of subatomic dimensions. This setup can either be at a high or low temperature, emulating the two baths found in conventional heat engines. Controlling the parameters influencing how such quantum heat engine models work could dramatically increase our power to manipulate the quantum states of the coupled atomcavity, and accelerate our ability to process quantum information. In order for this to work, we have to find new ways of improving the efficiency of quantum heat engines. In a study published in EPJ D, KaiWei Sun and colleagues from Beihang University, Beijing, China, show methods for controlling the output power and efficiency of a quantum thermal engine based on the twoatom cavity. In the familiar heat engine model at macroscopic scale, referred to as the Carnot heat engine, the efficiency increases as a function of the ratio between the temperatures of the lowand hightemperature baths. By comparison, the efficiency of twolevel quantum heat engines is related to the level of quantum entanglement in these two states, which are either at a low or a high temperature, and display the same probability of being occupied.
Open calls for papers

EPJE Topical Issue: Dielectric Spectroscopy Applied to Soft Matter

EPJA Topical Issue: The first Neutron Star Merger Observation  Implications for Nuclear Physics

EPJ B Special Issue: NonLinear and Complex Dynamics in Semiconductors and Related Materials

EPJ D Topical Issue: Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces (MPS 2018)

EPJ E Topical Issue: Branching Dynamics at Mesoscopic Scale

EPJ E Call for papers: Thermal nonequilibrium phenomena in soft matter

EPJ ST Special Issue: Microscopic dynamics, chaos and transport in nonequilibrium processes

EPJ AM Call for papers: Themed Issue on Terahertz metamaterials

EPJ D Topical Issue: Quantum Correlations

EPJ ST Special Issue: Topological States of Matter: Theory and Applications

EPJ B Special Issue: Complex Systems Science meets Matter and Materials

EPJ B Special Issue on Multiscale Materials Modeling

EPJ Data Science: Thematic series on human mobility

EPJ Data Science: Thematic Series on Individual and Collective Human Mobility: Description, Modelling, Prediction

EPJ Quantum Technology: Thematic Series on Space Applications of Quantum Technology

EPJ Techniques and Instrumentation: Thematic Series on Novel Plasma Diagnostics