Bound information in the environment: Environment learns more than it will reveal

Quantum systems loose their properties due to information leaking into environment. On the other hand, we perceive the outer world through the environment. We show here that there is a gap between what leaks into the environment and what can be extracted from it. We quantify this gap, using the prominent example of the Caldeira-Leggett model, by demonstrating that information extraction is limited by its own lengthscale, called distinguishability length, larger than the celebrated thermal de Broglie wavelength, governing the decoherence. We also introduce a new integral kernel, called Quantum Fisher Information kernel, complementing the well-known dissipation and noise kernels, and show a type of disturbance-information gain trade-off, similar to the famous fluctuation-dissipation relation. Our results show that the destruction of quantum coherences and indirect observations happen at two different scales with a "gray zone" in between. This puts intrinsic limitations on capabilities of indirect observations.Comment: 10 pages, 1 figur

Vibration damping of the anti-vibration platform intended for use in combination with audio/music devices

The article presents research on the damping properties of an anti-vibration platform (designed and manufactured by Stacore), which is intended for use in combination with high class audio devices. The platform comprises two parts that are capable of passive vibration damping. The design of this platform is unique and has been developed by applying several technical solutions in a combination not found on any other anti-vibration platform on the audio market. These solutions are described in the article. The first part of the platform is pneumatically operated and the second part uses ball bearings. The casing also fulfils the most important function – vibration damping. It is made of amorphous slate (known for its good vibration-damping properties) and includes a metal plate covered with a special visco-elastic layer that fulfils the role of binding material. The first part of the platform realises the pneumatic damping. It comprises four elastomer pneumatic springs, each with its own air tank. The air tanks are designed to operate at a maximum pressure of 5 bar. The second vibration-damping part of the platform is located above the first part (pneumatic) and consists of ball bearings, used for the isolation of transverse vibration, being relatively difficult to deal with pneumatic springs. The upper part consists of three bearings, each of which comprises of a polished, deep hardened steel racings and a ball made of tungsten carbide. The scientific literature describes many solutions enabling vibration damping, including many anti-vibration platforms. However, the literature lacks the descriptions of analyses conducted on anti-vibration platforms for audio devices. This article is a novelty in the literature as it concerns the experimental research aimed at verifying the vibration-damping capacity of the anti-vibration platform that can be used with audio devices owned by people who appreciate high-quality music. The article describes in detail the whole measurement procedure applied to the vibration damping platform. For research purposes, the anti-vibration platform was suspended on flexible ropes. At first, an electromagnetic vibration exciter was attached to the base on which the platform rested, and then the displacements of the upper and lower part of the platform were measured using laser sensors. Based on these signals, the vibration damping capability (transmissibility) of the platform was determined in two mutually perpendicular directions. In addition to the graph that shows the vibration damping capability of the anti-vibration platform, the signals of the applied force and displacements measured during the research are also presented in this article

Gaussian work extraction from random Gaussian states is nearly impossible

Quantum thermodynamics can be naturally phrased as a theory of quantum state transformation and energy exchange for small-scale quantum systems undergoing thermodynamical processes, thereby making the resource theoretical approach very well suited. A key resource in thermodynamics is the extractable work, forming the backbone of thermal engines. Therefore it is of interest to characterize quantum states based on their ability to serve as a source of work. From a near-term perspective, quantum optical setups turn out to be ideal test beds for quantum thermodynamics; so it is important to assess work extraction from quantum optical states. Here, we show that Gaussian states are typically useless for Gaussian work extraction. More specifically, by exploiting the ``concentration of measure'' phenomenon, we prove that the probability that the Gaussian extractable work from a zero-mean energy-bounded multimode random Gaussian state is nonzero is exponentially small. This result can be thought of as an $\epsilon$-no-go theorem for work extraction from Gaussian states under Gaussian unitaries, thereby revealing a fundamental limitation on the quantum thermodynamical usefulness of Gaussian components.Comment: 7+8 pages, 2 figures, close to the published versio

The origin of objectivity in all fundamental causal theories

An essential scientific question is whether a description of Nature can be formulated without knowing its ultimate physical theory, but instead by simply relying on some fundamental principles that account for experimental data. Here we show that for the emergence of objectivity the answer is positive, and it is based solely on the Causality principle. In this respect, we formulate a necessary requirement for a theory to be fundamental, illustrating its usefulness with a non-trivial example. We provide a natural definition of the decoherence process valid in all fundamental causal theories, and demonstrate its extreme departure from quantum decoherence in its behavior. Remarkably, despite the broad range of theories and process studied, we prove that the so-called Spectrum Broadcast Structure characterizes all objective states in every fundamental causal theory, exactly as in quantum mechanics. Our results, including especially the stark contrast between the extremely varied decoherence behavior and the universal features of objectivity, promote the emergence of classicality and objective properties to a new and promising theory-independent line of research.Comment: 10+14 pages, 7+7 figures, new results, completely new perspectiv