We revisit well-established concepts of epidemiology, the Ising-model, and percolation theory. Also, we employ a spin S = 1/2 Ising-like model and a (logistic) Fermi–Dirac-like function to describe ...the spread of Covid-19. Our analysis show that: (i) in many cases the epidemic curve can be described by a Gaussian-type function; (ii) the temporal evolution of the accumulative number of infections and fatalities follow a logistic function; (iii) the key role played by the quarantine to block the spread of Covid-19 in terms of an interacting parameter between people. In the frame of elementary percolation theory, we show that: (i) the percolation probability can be associated with the probability of a person being infected with Covid-19; (ii) the concepts of blocked and non-blocked connections can be associated, respectively, with a person respecting or not the social distancing. Yet, we make a connection between epidemiological concepts and well-established concepts in condensed matter Physics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The temperature change under adiabatic stress, i.e., the elastocaloric effect, is a well-understood phenomenon and of particular interest due to its potential application in alternative ways for ...refrigeration. Here, we demonstrate that in the regime of low-temperatures (a few mK) real paramagnets can be magnetized when compressed adiabatically without applied magnetic field. Such adiabatic magnetization is a genuine many-body problem, stemming from the inherent dipolar mutual interactions between adjacent magnetic moments. We showcase experimental setups to carry out adiabatic magnetization and thus to access such a subtle effect. Perspectives of further investigations by controlling the mutual interactions in Bose-Einstein condensates in magnetic insulators and dipolar spin-ice systems via the adiabatic increase of temperature are also presented. Yet, we discuss the connection between the elastic Grüneisen parameter and the shift on the critical temperature of second-order phase transitions under adiabatic stress, as well as its connection with the Ehrenfest relation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In real paramagnets, there is always a subtle many-body contribution to the system's energy, which can be regarded as a small effective local magnetic field (B
). Usually, it is neglected, since it ...is very small when compared with thermal fluctuations and/or external magnetic fields (B). Nevertheless, as both the temperature (T) → 0 K and B → 0 T, such many-body contributions become ubiquitous. Here, employing the magnetic Grüneisen parameter (Γ
) and entropy arguments, we report on the pivotal role played by the mutual interactions in the regime of ultra-low-T and vanishing B. Our key results are: i) absence of a genuine zero-field quantum phase transition due to the presence of B
; ii) connection between the canonical definition of temperature and Γ
; and iii) possibility of performing adiabatic magnetization by only manipulating the mutual interactions. Our findings unveil unprecedented aspects emerging from the mutual interactions.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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•Use of the here-proposed electric Grnneisen parameter to quantify the electrocaloric effect.•Forecast of giant caloric effects close to any critical end point.•Proposal of ...key-ingredients to enhance caloric effects.•Connection between enhanced electrocaloric effects and quantum ferroelectrics.
The electrocaloric (EC) effect, i.e., the reversible temperature change due to adiabatic variations of the electric field, is of great interest due to its potential technological applications in refrigeration. Based on entropy arguments, we present a new framework to attain giant EC effects. Our findings are fourfold: (i) we employ the recently-proposed electric Grüneisen parameter ΓE to quantify the EC effect and discuss its advantages over the existing so-called electrocaloric strength; (ii) prediction of giant caloric effects close to any critical end point; (iii) proposal of potential key-ingredients to enhance the EC effect; (iv) demonstration of ΓE as a proper parameter to probe quantum ferroelectricity in connection with the celebrated Barrett's formula. Our findings enable us to interpret the recently-reported large EC effect at room-temperature in oxide multilayer capacitors 5, paving thus the way for new venues in the field.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Protein compartmentalization in the frame of a liquid-liquid phase separation is a key mechanism to optimize spatiotemporal control of biological systems. Such a compartmentalization process reduces ...the intrinsic noise in protein concentration due to stochasticity in gene expression. Employing Flory-Huggins solution theory, Avramov/Casalini's model, and the Grüneisen parameter, we unprecedentedly propose a cellular Griffiths-like phase (CGLP), which can impact its functionality and self-organization. The here-proposed CGLP is key ranging from the understanding of primary organisms' evolution to the treatment of diseases. Our findings pave the way for an alternative Biophysics approach to investigate coacervation processes.
•Pioneering proposal of a cellular Griffiths-like phase to describe protein compartmentalization.•Possible impact on disease's treatment, homochirality, and origin of primary organisms.•Biophysics approach to analytically extract protein dynamics within a cell.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
For a perfect fluid, pressure p and energy density ρ are related via the equation of state (EOS) ω=p/ρ, where ω is the EOS parameter, being its interpretation usually constrained to a numerical value ...for each universe era. Here, based on the Mie–Grüneisen EOS, we show that ω is recognized as the effective Grüneisen parameter Γeff, whose singular contribution, the so-called Grüneisen ratio Γ, quantifies the barocaloric effect. Our analysis suggests that the negative p associated with dark-energy implies a metastable state and that in the dark-energy-dominated era ω is time-dependent, which reinforces recent proposals of a time-dependent cosmological constant. Furthermore, we demonstrate that Γeff is embodied in the energy–momentum stress tensor in the Einstein field equations, enabling us to analyse, in the frame of an imperfect fluid picture, anisotropic effects of the universe expansion. We propose that upon going from decelerated- to accelerated-expansion, a phase transition-like behaviour can be inferred. Yet, our analysis in terms of entropy, Γ, and a by us adapted version of Avramov/Casalini’s model to Cosmology unveil hidden aspects related to the expansion of the universe. Our findings pave the way to interpret cosmological phenomena in connection with concepts of condensed matter Physics via Γeff.
•Recognition of the EOS parameter ω for the perfect fluid as the effective Grüneisen parameter Γeff.•Proposal that ω is time-dependent in the dark energy-dominated era.•Change from the decelerated- to accelerated-expansion is a phase-transition-like behaviour.•Demonstration that Γeff is embedded in the celebrated Einstein field equations through Tμν.•Continuous cooling of the universe is a barocaloric effect, quantified by Γ.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We explore the coexistence region in the vicinity of the Mott critical end point employing a compressible cell spin-\(1/2\) Ising-like model. We analyze the case for the spin-liquid candidate ...\(\kappa\)-(BEDT-TTF)\(_2\)Cu\(_2\)(CN)\(_3\), where close to the Mott critical end point metallic puddles coexist with an insulating ferroelectric phase. Our results are fourfold: \(i\)) a universal divergent-like behavior of the Gr\"uneisen parameter upon crossing the first-order transition line; \(ii\)) based on scaling arguments, we show that within the coexistence region, for \(any\) system close to the critical point, the relaxation time is entropy-dependent; \(iii\)) we propose the electric Gr\"uneisen parameter \(\Gamma_E\), which quantifies the electrocaloric effect; \(iv\)) we identify the metallic/insulating coexistence region as an electronic Griffiths-like phase. Our findings suggest that \(\Gamma_E\) governs the dielectric response close to the critical point and that an electronic Griffiths-like phase emerges in the coexistence region.
We revisit well-established concepts of epidemiology, the Ising-model, and percolation theory. Also, we employ a spin \(S\) = 1/2 Ising-like model and a (logistic) Fermi-Dirac-like function to ...describe the spread of Covid-19. Our analysis reinforces well-established literature results, namely: \emph{i}) that the epidemic curves can be described by a Gaussian-type function; \emph{ii}) that the temporal evolution of the accumulative number of infections and fatalities follow a logistic function, which has some resemblance with a distorted Fermi-Dirac-like function; \emph{iii}) the key role played by the quarantine to block the spread of Covid-19 in terms of an \emph{interacting} parameter, which emulates the contact between infected and non-infected people. Furthermore, in the frame of elementary percolation theory, we show that: \emph{i}) the percolation probability can be associated with the probability of a person being infected with Covid-19; \emph{ii}) the concepts of blocked and non-blocked connections can be associated, respectively, with a person respecting or not the social distancing, impacting thus in the probability of an infected person to infect other people. Increasing the number of infected people leads to an increase in the number of net connections, giving rise thus to a higher probability of new infections (percolation). We demonstrate the importance of social distancing in preventing the spread of Covid-19 in a pedagogical way. Given the impossibility of making a precise forecast of the disease spread, we highlight the importance of taking into account additional factors, such as climate changes and urbanization, in the mathematical description of epidemics. Yet, we make a connection between the standard mathematical models employed in epidemics and well-established concepts in condensed matter Physics, such as the Fermi gas and the Landau Fermi-liquid picture.
The electrocaloric effect (ECE), i.e., the reversible temperature change due
to the adiabatic variation of the electric field, is of great interest due to
its potential technological applications. ...Based on entropy arguments, we
present a new framework to attain giant ECE. Our findings are fourfold: $i$) we
employ the recently-proposed electric Gr\"uneisen parameter $\Gamma_E$ to
quantify the ECE and discuss its advantages over the existing so-called
electrocaloric strength; $ii$) prediction of giant caloric effects $close$ to
$any$ critical end point; $iii$) proposal of potential key-ingredients to
enhance the ECE; $iv$) demonstration of $\Gamma_E$ as a proper parameter to
probe quantum ferroelectricity in connection with the celebrated Barrett's
formula. Our findings enable us to interpret the recently-reported large ECE at
room-temperature in oxide multilayer capacitors Nature 575, 468 (2019),
paving thus the way for new venues in the field.
In real paramagnets, there is always a subtle many-body contribution to the system's energy, which can be regarded as a small effective local magnetic field \(B_{loc}\). Usually, it is neglected, ...since it is very small when compared with thermal fluctuations and/or external magnetic fields \(B\). Nevertheless, as both the temperature \(T \rightarrow\) 0K and \(B \rightarrow\) 0T, such many-body contributions become ubiquitous. Here, employing the magnetic Gr\"uneisen parameter \(\Gamma_{mag}\) and entropy arguments, we report on the pivotal role played by the mutual interactions in the regime of ultra-low-\(T\) and vanishing \(B\). Our key results are: \(i\)) absence of a genuine zero-field quantum phase transition due to the presence of \(B_{loc}\); \(ii\)) connection between the canonical definition of temperature and \(\Gamma_{mag}\); and \(iii\)) possibility of performing adiabatic magnetization by only manipulating the mutual interactions. Our findings unveil unprecedented aspects emerging from the mutual interactions.
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