1,648 Results Found

The Berezinskii–Kosterlitz–Thouless (BKT) transition is the prototype of a phase transition driven by the formation and interaction of topological defects in two-dimensional (2D) systems. In typical models, these are vortices: above a tra...

Phase transitions—both classical and quantum types—are the perfect playground for appreciating universality at work. Indeed, the fine details become unimportant and a classification in very few universality classes is possible. Very recen...

Solving the eigenproblems of Hermitian matrices is a significant problem in many fields. The quantum resonant transition (QRT) algorithm has been proposed and demonstrated to solve this problem using quantum devices. To better realize the capabilitie...

The optomechanics shows a great potential in quantum control and precise measurement due to appropriate mechanical control. Here we theoretically study the quantum phase transition in a hybrid atom-optomechanical cavity with an external force. Our st...

In this paper, we investigate the effect of the Dicke quantum phase transition on the speed of evolution of the system dynamics. At the phase transition point, the symmetry associated with the system parity operator begins to break down. By comparing...

Phase transitions happen at critical values of the controlling parameters, such as the critical temperature in classical phase transitions, and system critical parameters in the quantum case. However, true criticality happens only at the thermodynami...

Quantum transition simulations on complex networks capture superposition, interference, and decoherence beyond classical stochastic models. This review provides a unified, mathematically rigorous account of the theory, algorithms, and cross-domain ap...

In this paper, we investigate the effect of the Dicke quantum phase transition on the Berry phase of the two impurity qubits. The two impurity qubits only have dispersive interactions with the optical field of the Dicke quantum system. Therefore, the...

We investigate the coupled-top model, which describes two large spins interacting along both x and y directions. By tuning coupling strengths along distinct directions, the system exhibits different symmetries, ranging from a discrete $Z_2$ to a continu...

Despite extensive research on semiconductor materials, the influence of temperature and magnetic field on the optical quantum transitions within semiconductors remains insufficiently understood. We therefore investigated the Optical Quantum Transitio...

Transition metal dichalcogenide-based quantum dots are promising materials for applications in diverse fields, such as sensors, electronics, catalysis, and biomedicine, because of their outstanding physicochemical properties. In this study, we propos...

A spin-boson-like model with two interacting qubits is analysed. The model turns out to be exactly solvable since it is characterized by the exchange symmetry between the two spins. The explicit expressions of eigenstates and eigenenergies make it po...

Crystalline urea undergoes polymorphic phase transition induced by high pressure. Form I, which is the most stable form at normal conditions and Form IV, which is the most stable form at 3.10 GPa, not only crystallize in various crystal systems but a...

Perpendicular magnetic tunnel junctions provide a technologically important design platform for studying metal-insulator-metal heterostructure materials. Accurate characterization of the sensitivity of their electronic structure to proximity coupling...

We report here on the direct observation of distinct two-photon transition channels in glutathione-capped (GSH) CdTe quantum dots (QDs) in a very strong confinement regime. CdTe-GSH QDs with different average diameters (2.5, 3.0, and 3.3 nm) were syn...

The stimulated assembly/disassembly of particles is a technique allowing for precise spatial and temporal control over the resulting structures to be realized. The application of a photosensitive liquid crystal (LC) allows the use of a photo-initiate...

We present a new theoretical framework for which-path determination in an entangled-photon double-slit experiment. In the present proposal, the availability of which-path information is governed by the intrinsic quantum transition probability (IQTP)...

Magnetic two-dimensional (2D) van der Waals materials have attracted tremendous attention because of their high potential in spintronics. In particular, the quantum anomalous Hall (QAH) effect in magnetic 2D layers shows a very promising prospect for...

We introduce a quantum version for the statistical complexity measure, in the context of quantum information theory, and use it as a signaling function of quantum order–disorder transitions. We discuss the possibility for such transitions to ch...

Third-generation solar cells, including dye-sensitized solar cells (DSSCs) and quantum dot-sensitized solar cells (QDSSCs), have been associated with low-cost material requirements, simple fabrication processes, and mechanical robustness. Hence, coun...

In this paper, we study the line-shape (LS), which indicates the amount of absorbed energy, and the line-width (LW), which indicates the scattering factor, according to the vibrational direction of the externally applied energy in the electron–...

Simulating the real-time dynamics of gauge theories represents a paradigmatic use case to test the hardware capabilities of a quantum computer, since it can involve non-trivial input states’ preparation, discretized time evolution, long-distanc...

Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials scienc...

We investigate a generalized Dicke model by introducing two interacting spin ensembles coupled with a single-mode bosonic field. Apart from the normal to superradiant phase transition induced by the strong spin–boson coupling, interactions betw...

We employ two different Lipkin-like, exactly solvable models so as to display features of the competition between different fermion–fermion quantum interactions (at finite temperatures). One of our two interactions mimics the pairing interaction resp...

We present here a theory of the electronic properties of quasi two-dimensional quantum dots made of topological insulators. The topological insulator is described by either eight band $\overrightarrow{k}·\overrightarrow{p}$ Hamiltonian or by a four-band $\overrightarrow{k}\&middo$...

For the identification of non-trivial quantum phase, we exploit a Bell-type correlation that is applied to the one-dimensional spin-1 XXZ chain. It is found that our generalization of bipartite Bell correlation can take a decomposed form of transvers...

Phase transition in quantum mechanics is interpreted as an evolution, at the end of which, typically, a parameter-dependent and Hermitizable Hamiltonian $H\left(g\right)$ loses its observability. In the language of mathematics, such a “quantum catastrophe&r...

As the simplest and most fundamental model describing the interaction between light and matter, a breakdown in the rotating wave approximation of the Rabi model leads to phase transition versus coupling strength when the frequency of the qubit greatl...

We investigate the phase transitions and the properties of the topological insulator in InGaN/GaN and InN/InGaN double quantum wells grown along the [0001] direction. We apply a realistic model based on the nonlinear theory of elasticity and piezoele...

We investigate the classical limit of the dynamics of a semiclassical system that represents the interaction between matter and a given field. On using as a quantifier the q- Complexity, we find that it describes appropriately the quantum-classical t...

Thermal management by controlling radiative energy exchange has emerged as a sustainable route for regulating temperature and reducing energy consumption. Conventional thermal–management surfaces with static optical properties continue to find...

We investigate the classical limit of the semiclassical evolution with reference to a well-known model that represents the interaction between matter and a given field. This is done by recourse to a special statistical quantifier called the “symbolic...

We show that a special entropic quantifier, called the statistical complexity, becomes maximal at the transition between super-Poisson and sub-Poisson regimes. This acquires important connotations given the fact that these regimes are usually associa...

As quantum computing advances, current cryptographic protocols are increasingly vulnerable to quantum attacks, particularly those based on Public Key Infrastructure (PKI) like RSA or Elliptic Curve Cryptography (ECC). This paper presents a comprehens...

Thulium iron garnet (Tm₃Fe₅O₁₂, TmIG) is a promising material for next-generation spintronic and quantum technologies owing to its high Curie temperature and strong perpendicular magnetic anisotropy. However, conventional magnetometry techniques are...

n-type Ge/SiGe asymmetric coupled quantum wells represent the building block of a variety of nanoscale quantum devices, including recently proposed designs for a silicon-based THz quantum cascade laser. In this paper, we combine structural and spectr...

The discovery of dynamical quantum phase transitions (DQPTs) has fundamentally challenged the traditional view that phase transitions only occur in thermal equilibrium. Experimental platforms and 1D numerical methods, like matrix product states (MPS)...

The studies of the interband electron transition energy in multiple Hg_1-xCd_xTe/Hg_1-yCd_yTe quantum wells (MQWs) at room temperature were carried out. The MQWs were grown on the (013) GaAs substrate by molecular beam epitaxy, with the layer composition...

Real time quantum dynamics of the spontaneous translational symmetry breakage in the early stage of photo-induced structural phase transitions is reviewed and supplementally explained, under the guide of the Toyozawa theory, which is exactly in compl...

Within density functional theory (DFT), where the density is the fundamental variable, quantum phase transitions (QPTs) can be formulated through a Hamiltonian $\widehat{H}={\widehat{H}}_0+{\sum }_i{\xi }_i{\widehat{A}}_i$, such that the control parameters $\left\{{\xi }_i\right\}$ are in bije...

In this work, we proposed a smooth transition wave equation from a quantum to classical regime in the framework of von Neumann formalism for ensembles and then obtained an equivalent scaled equation. This led us to develop a scaled statistical theory...

Carbon quantum dots (CQDs) are an excellent eco-friendly fluorescence material, ideal for various ecological testing systems. Herein, we establish uniform microwave synthesis of the group of carbon quantum dots with specific functionalization of ethy...

We investigated the conduction- and valence-confined energy levels and first band-to-band transition energies of a type-II InAs/GaSb multi-quantum-well at 77 K and room temperature for various well and barrier thicknesses. We calculated the electron...

The emergence of classicality from a stochastic quantum system through decoherence is investigated. We consider the case where the parameters, such as mass, frequency, and the damping coefficient, vary with time. The invariant operator theory is empl...

Telecommunication infrastructures rely on cryptographic protocols designed for long-term confidentiality, yet data exchanged today faces future exposure when adversaries acquire quantum or large-scale computational capabilities. This harvest-now, dec...

Quantum systems with dynamical symmetries have conserved quantities that are preserved under coherent control. Therefore, such systems cannot be completely controlled by means of only coherent control. In particular, for such systems, the maximum tra...

A variety of models of inflation in the early Universe have been proposed and applied to describe successfully the origin of all possible structures in the Universe. On the other hand, inflation theory is still phenomenological and needs systematic p...

We investigate finite-size effects on the density-driven deconfinement phase transition in Quantum Chromodynamics (QCD) using a phase coexistence model of hadronic and quark–gluon plasma (QGP) phases in a finite size. The QGP is described via the MIT...

We present a comparison of a classical and a quantum mechanical calculation of the motion of K⁺ ions in the highly conserved KcsA selectivity filter motive of voltage gated ion channels. We first show that the de Broglie wavelength of thermal ions is...