Article
Astronomy & Astrophysics
Matthew J. Lake, Anucha Watcharapasorn
Summary: The purpose of this paper is to challenge the assumptions of modified commutation relations, which form the basis of contemporary models of generalised uncertainty relations (GURs). By reviewing various theoretical problems associated with modified commutator models, the paper proposes a simple assumption that can generate GURs without modifying the basic form of the canonical Heisenberg algebra. This assumption has significant implications for the quantisation of space-time and gravity.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Article
Physics, Multidisciplinary
Rodolfo R. Soldati, Durga B. R. Dasari, Jor Wrachtrup, Eric Lutz
Summary: The thermodynamic performance of a minimal three-qubit heat-bath algorithmic cooling refrigerator is investigated theoretically and experimentally. The coefficient of performance, cooling power, and polarization of the target qubit are analytically computed for an arbitrary number of cycles, considering realistic experimental imperfections. The fundamental upper bounds of these values are determined in the ideal reversible limit, and it is shown that these values can be approached experimentally using a system of three qubits in a nitrogen-vacancy center in diamond.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
A. Alonso-Serrano, M. Liska
Summary: By heuristically deriving the Hawking temperature and Bekenstein entropy from the existence of a minimal resolvable area, we found quantum gravity corrections that are qualitatively consistent with results obtained by other methods. The size of the minimal area is constrained by semiclassical black hole physics, particularly by the entropy content of Hawking radiation. The derivation method is also applied to finding the Unruh temperature associated with causal diamonds and establishing a new relation between this temperature and the entropy of the causal diamond's horizon.
Article
Physics, Mathematical
Alexey Kuzmin
Summary: This article investigates the image of the universal enveloping C-*;-algebra of q-canonical commutation relations in the Fock representation, and proves that under certain conditions, the image is similar or equal to the image when q is equal to zero.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Jaewoo Joo, Timothy P. Spiller
Summary: Recent progress in quantum simulation and algorithms has led to a rapid expansion in capabilities. A new method is proposed to directly investigate the properties of a time-dependent density operator. By using quantum commutation simulators, the method allows for the computation of the expectation value of the commutation relation and the rate of change of the density operator. This approach has applications in quantum eigen-vector solving and decoherence investigation.
NEW JOURNAL OF PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Takuya Kamijima, Sosuke Ito, Andreas Dechant, Takahiro Sagawa
Summary: This article investigates the driving forces that push a system out of equilibrium, such as time-dependent and nonconservative forces. The dissipation of the system can then be decomposed into two nonnegative parts, known as excess and housekeeping entropy productions. Thermodynamic uncertainty relations are derived for these entropy components, which can serve as useful tools for estimating their individual contributions. A decomposition of an arbitrary current into housekeeping and excess parts is also introduced, providing lower bounds for their respective entropy productions. Additionally, a geometric interpretation of the decomposition is presented, revealing that the uncertainties of the two components are not independent and must obey a joint uncertainty relation, resulting in a tighter bound on the total entropy production. The findings are applied to illustrate the physical interpretation of current components and how to estimate entropy production.
Article
Physics, Multidisciplinary
Geng Li, Jin-Fu Chen, C. P. Sun, Hui Dong
Summary: Shortcuts to isothermality are a strategy for driving a system to its equilibrium states and evaluating the impact of control. Finding the optimal scheme to minimize energy cost is crucial, and it has been proven to be equivalent to finding the geodesic path in the space of control parameters. This equivalence provides a systematic and universal approach to finding optimal control for reducing energy cost.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Li-Hua Wang, Meng-Sen Ma
Summary: This paper re-derives the black hole entropy of static spherically symmetric black holes based on the concept of fractal black hole horizon. The temperatures and heat capacities of Schwarzschild, Reissner-Nordstrom, and RN-AdS black holes are calculated, showing that these black holes are thermodynamically stable. The heat capacity of RN-AdS black hole exhibits Schottky anomaly-like behavior, indicating the existence of discrete energy levels and restricted microscopic degrees of freedom.
Article
Mechanics
J. D. Goddard
Summary: This paper addresses the conflict between interpretations of thermoelectricity based on the reversible thermodynamics of Thomson and the irreversible thermodynamics of Onsager. By modifying the Maxwellian relaxation and offering a modern interpretation, it reveals thermoelectricity as analogous to fluid-mechanical transport processes.
Article
Astronomy & Astrophysics
Sudipta Hensh, Stefano Liberati, Vincenzo Vitagliano
Summary: This study investigates the possible perturbations of black hole event horizons induced by matter with spin, and extends the derivation of the Hawking-Hartle formula in the presence of torsion. When focusing on theories with a nonzero component of the torsion tensor, it is found that the tidal heating phenomenon is modified by additional torsion-dependent terms, consistent with previous research based on Jacobson's spacetime thermodynamics approach. These findings have important implications for both phenomenological and theoretical aspects, such as changes in the Bondi mass associated with observed gravitational radiation and modifications to the Hawking radiation spectrum of evaporating black holes.
Article
Astronomy & Astrophysics
Pasquale Bosso
Summary: Several approaches to quantum gravity suggest the existence of a minimal measurable length at high energies, contradicting the Heisenberg Uncertainty Principle. To address this issue, the Generalized Uncertainty Principle is introduced in phenomenological approaches to quantum gravity, affecting several features of quantum mechanics, such as the exclusion of position eigenstates in models with a minimal length.
Article
Physics, Fluids & Plasmas
Jin-Fu Ma, Jin-Fu Chen, C. P. Sun, Hui Dong
Summary: Landauer's principle imposes a fundamental limit on the energy cost of perfectly initializing a classical bit, but in practical operations, the finite operation time leads to an increase in energy cost. Specifically, when initializing the bit, the smaller the error, the higher the energy cost. A finite-time isothermal process can be used for bit initialization, and an optimal protocol to minimize the energy cost is proposed.
Article
Mathematics, Interdisciplinary Applications
Stefano Gherardini, Lorenzo Buffoni, Guido Giachetti, Andrea Trombettoni, Stefano Ruffo
Summary: This paper discusses the statistical description of energy fluctuations in non-equilibrium regimes generated by the interaction between a quantum system and a measurement apparatus. The exchanged heat probability density function and characteristic function are derived and interpreted to quantify the information about energy fluctuations. The validity conditions of the fluctuation theorem and the late-time properties of the heat characteristic function are also analyzed. The paper further explores the changes in energy fluctuation relations when the system operates in the quantum Zeno regime, and illustrates the theoretical results with two-and three-levels quantum systems.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Physics, Fluids & Plasmas
Gianluca Francica
Summary: This article discusses the significance of fluctuation theorems in nonequilibrium thermodynamics, derives a thermodynamic uncertainty relation, and examines the relationship between this relation and the correlation between entropy and observables.
Article
Mathematics
Vladimir Georgescu, Andrei Iftimovici
Summary: We study the C*-algebra generated by the field operators associated with a symplectic space Xi, and find that it is graded by the semilattice of all finite dimensional subspaces of Xi. If Xi is finite dimensional, we provide a simple intrinsic description of the grading components, show that the self-adjoint operators affiliated to the algebra have a many channel structure similar to that of N-body Hamiltonians, and describe their essential spectrum using a HVZ theorem. We also identify a large class of operators affiliated to the algebra.
JOURNAL OF FUNCTIONAL ANALYSIS
(2023)
Article
Physics, Multidisciplinary
Tinggui Chen, Baizhan Xia, Dejie Yu, Chuanxing Bi
Summary: This study proposes a gradient phononic crystal structure for enhanced acoustic sensing. By breaking the symmetry of the PC structure, topologically protected edge states are introduced, resulting in topological acoustic rainbow trapping. The robustness and enhancement properties are verified numerically and experimentally.
