Noncommutative Harmonic Oscillator Research Articles

Spectral Asymptotic Properties of Semiregular Non-commutative Harmonic Oscillators

We study here the spectral Weyl asymptotics for a semiregular system, extending to the vector-valued case results of Helffer and Robert, and more recently of Doll, Gannot and Wunsch. The class of systems considered here contains the important example of the Jaynes–Cummings system that describes light-matter interaction.

On the spectral zeta function of second order semiregular non-commutative harmonic oscillators

In this paper we give a meromorphic continuation of the spectral zeta function for second order semiregular Non-Commutative Harmonic Oscillators (NCHO). By “semiregular systems” we mean systems with terms with degree of homogeneity scaling by 1 in their asymptotic expansion. As an application of our results, we first compute the meromorphic continuation of the Jaynes-Cummings (JC) model spectral zeta function. Then we compute the spectral zeta function of the JC generalization to a 3-level atom in a cavity. For both of them we show that it has only one pole in 1.

Apéry-like numbers for non-commutative harmonic oscillators and automorphic integrals

The purpose of the present paper is to study the number theoretic properties of the special values of the spectral zeta functions of the non-commutative harmonic oscillator (NcHO), especially in relation to modular forms and elliptic curves from the viewpoint of Fuchsian differential equations, and deepen the understanding of the spectrum of the NcHO. We study first the general expression of special values of the spectral zeta function $\zeta\_Q(s)$ of the NcHO at $s=n$ $(n=2,3,\dots)$ and then the generating and meta-generating functions for Apéry-like numbers defined through the analysis of special values $\zeta\_Q(n)$. Actually, we show that the generating function $w\_{2n}$ of such Apéry-like numbers appearing (as the “first anomaly”) in $\zeta\_Q(2n)$ for $n=2$ gives an example of automorphic integral with rational period functions in the sense of Knopp, but still a better explanation remains to be clarified explicitly for $n>2$. This is a generalization of our earlier result on showing that $w\_2$ is interpreted as a $\Gamma(2)$-modular form of weight $1$. Moreover, certain congruence relations over primes for “normalized” Apéry-like numbers are also proven. In order to describe $w\_{2n}$ in a similar manner as $w\_2$, we introduce a differential Eisenstein series by using analytic continuation of a classical generalized Eisenstein series due to Berndt. The differential Eisenstein series is actually a typical example of the automorphic integral of negative weight. We then have an explicit expression of $w\_4$ in terms of the differential Eisenstein series. We discuss also shortly the Hecke operators acting on such automorphic integrals and relating Eichler’s cohomology group.

Collapse-revival of entanglement in a non-commutative harmonic oscillator revealed via coherent states and path integral

Abstract We develop an approach using coherent states and path integral to investigate the dynamics of entanglement in a simple two-dimensional non-commutative harmonic oscillator. We start by employing a Bopp shift to convert the Hamiltonian describing the system into a commutative equivalent one. This allows us to construct coherent states and calculate the propagator in standard way. By deriving the explicit expression of the time-dependent coherent states and considering its connection with the number states, we provide exact results for evaluating the degree of entanglement between the ground state and any excited state through the purity function. The interesting emerging result is that, as long as the non-commutativity parameter is non-zero, our system exhibits the phenomenon of collapse and revival of entanglement.

Emergent time crystals from phase-space noncommutative quantum mechanics

It has been argued that the existence of time crystals requires a spontaneous breakdown of the continuous time translation symmetry so to account for the unexpected non-stationary behavior of quantum observables in the ground state. Our point is that such effects do emerge from position (qˆi) and/or momentum (pˆi) noncommutativity, i.e., from [qˆi,qˆj]≠0 and/or [pˆi,pˆj]≠0 (for i≠j). In such a context, a predictive analysis is carried out for the 2-dim noncommutative quantum harmonic oscillator through a procedure supported by the Weyl-Wigner-Groenewold-Moyal framework. This allows for the understanding of how the phase-space noncommutativity drives the amplitude of periodic oscillations identified as time crystals. A natural extension of our analysis also shows how the spontaneous formation of time quasi-crystals can arise.

On the collapse revival of entanglement in a two-dimensional noncommutative harmonic oscillator: An algebraic approach

In this paper, we employ an algebraic approach to investigate the dynamics of entanglement in a two-dimensional noncommutative harmonic oscillator. We start by using the so-called the Bopp shift to convert the Hamiltonian describing the system into an equivalent commutative one. This allows us to take advantage of the Schwinger oscillator construction of [Formula: see text] Lie algebra to reveal through the time evolution operator that there is a connection between the noncommutativity and entanglement. The degree of entanglement between the states is evaluated by using the purity function. The remarkable emerging feature is that, as long as the noncommutativity parameter is nonvanishing, the system exhibits the phenomenon of collapse and revival of entanglement.

A supercongruence relation among Ap

In 2006, Kimoto and Wakayama discussed a kind of Apéry-like numbers arising from the spectral zeta functions associated to the non-commutative harmonic oscillator. In this paper, we establish a supercongruence relation between this kind of Apéry-like numb

Nonlinear optical tomography of q-deformed entangled pair coherent states

We introduce entangled pair coherent states of a noncommutative harmonic oscillator operators associated with a q-deformed oscillator algebra. The definition of two-mode q-deformed operator and the decomposition of its eigenstates in terms of the q-deformed Fock states are obtained. The general solution of the recurrence relation of the first nondeformed quadrature is obtained. The asymptotic behavior of the general solution is studied, a complete expansion is derived, and also representations of the general solution in terms of the Gauss hypergeometric function are given. Also, we prove that the general solution is related to Meixner-Pollaczek orthogonal polynomial and calculate the weight function. The photons number distribution, the second order correlation function and the optical tomogram of the entangled pair coherent states are discussed. The recurrence relation for the first q-deformed quadrature is inferred. We evaluate the eigenstate of the q-deformed quadrature operator and give a numerical study for the optical tomogram of the q-deformed of the entangled pair coherent states. Finally, we show the change of the parameters in the entangled pair coherent states that connected with physical quantities and explain how they affect the format of optimal tomography.

Non-commutative space: boon or bane for quantum engines and refrigerators

Various quantum systems are considered as the working substance for the analysis of quantum heat cycles and quantum refrigerators. The ongoing technological challenge is how efficiently can a heat engine convert thermal energy to mechanical work. The seminal work of Carnot has proposed a fundamental upper limit-the Carnot limit on the efficiency of the heat engine. However, the heat engines can be operated beyond the fundamental upper limit by exploiting non-equilibrium reservoirs. Here, the change in the space structure introduces the non-equilibrium effect. So, a question arises whether a change in the space structure can provide any boost for the quantum engines and refrigerators. The efficiency of the heat cycle and the coefficient of performance (COP) of the refrigerator cycles in the non-commutative space are analyzed here. The efficiency of the quantum heat engines gets a boost with the change in the space structure than the traditional quantum heat engine but the effectiveness of the non-commutative parameter is less for the efficiency compared to the COP of the refrigerator. There is a steep boost for the coefficient of performance of the refrigerator cycles for the non-commutative space harmonic oscillator compared to the harmonic oscillator.

A generalized statistical complexity based on Rényi entropy of a noncommutative anisotropic oscillator in a homogeneous magnetic field

We calculate the shape Rényi and generalized Rényi complexity of a noncommutative anisotropic harmonic oscillator in a homogeneous magnetic field. To do so, we first obtain the Rényi entropy in position and momentum spaces of the exact normalized wave functions. We observe that shape Rényi and generalized Rényi complexities are monotone functions of noncommutative parameter ([Formula: see text]) in some short range in position space. We analyze the effect of the noncommutative parameter, the magnetic field and the anisotropy on shape Rényi and generalized Rényi complexities.

Bargmann-Type Transforms and Modified Harmonic Oscillators

We study some complete orthonormal systems on the real line. These systems are determined by Bargmann-type transforms, which are Fourier integral operators with complex-valued quadratic phase functions. Each system consists of eigenfunctions for a second-order elliptic differential operator like the Hamiltonian of the harmonic oscillator. We also study the commutative case of a certain class of systems of second-order differential operators called the non-commutative harmonic oscillators. By using the diagonalization technique, we compute the eigenvalues and eigenfunctions for the commutative case of the non-commutative harmonic oscillators. Finally, we study a family of functions associated with an ellipse in the phase plane. We show that the family is a complete orthogonal system on the real line.

Damped harmonic oscillator and bosonic string theory through noncommutativity

Some features of noncommutativity are investigated in this work. A noncommutative (NC) versions for the 2D harmonic oscillator and scalar field theory are obtained via the Noncommutative Mapping and fourfold discussion are presented: first, the Lagrangian of the damped harmonic oscillator (DHO), which was an original explanation for the dissipative process presenting in the atomic nuclei collision, is reobtained through noncommutativity. Here, we show that the NC parameter plays the role of the viscous damping coefficient; second, the NC harmonic oscillator is mapped into the bosonic string theory in the light cone frame, which appears as a bosonic string theory attached to a D3-brane; third, we discuss the connection between DHO and bosonic string attached to a D3-brane; fourth, the NC scalar field is indicating into 2D-NC harmonic oscillator.

Noncommutativeq-photon-added coherent states

We construct the photon added coherent states of a noncommutative harmonic oscillator associated to a $q$-deformed oscillator algebra. Various nonclassical properties of the corresponding system are explored, first, by studying two different types of higher order quadrature squeezing, namely the Hillery-type and the Hong--Mandel-type and, second, by testing the sub-Poissonian nature of photon statistics in higher order with the help of the correlation function and the Mandel parameter. By comparing our results with those of the usual harmonic oscillator, we notice that the quadratures and photon number distributions in noncommutative case are more squeezed for the same values of the parameters and, thus, the photon added coherent states of noncommutative harmonic oscillator may be more nonclassical in comparison to the ordinary harmonic oscillator.

Time-dependent q-deformed bi-coherent states for generalized uncertainty relations

We consider the time-dependent bi-coherent states that are essentially the Gazeau-Klauder coherent states for the two dimensional noncommutative harmonic oscillator. Starting from some q-deformations of the oscillator algebra for which the entire deformed Fock space can be constructed explicitly, we define the q-deformed bi-coherent states. We verify the generalized Heisenberg’s uncertainty relations projected onto these states. For the initial value in time, the states are shown to satisfy a generalized version of Heisenberg’s uncertainty relations. For the initial value in time and for the parameter of noncommutativity θ = 0, the inequalities are saturated for the simultaneous measurement of the position-momentum observables. When the time evolves, the uncertainty products are different from their values at the initial time and do not always respect the generalized uncertainty relations.

On the role of Schwinger’s SU(2) generators for simple harmonic oscillator in 2D Moyal plane

The Hilbert-Schmidt operator formulation of non-commutative quantum mechanics in 2D Moyal plane is shown to allow one to construct Schwinger's SU(2) generators. Using this the SU(2) symmetry aspect of both commutative and non-commutative harmonic oscillator are studied and compared. Particularly, in the non-commutative case we demonstrate the existence of a critical point in the parameter space of mass and angular frequency where there is a manifest SU(2) symmetry for a unphysical harmonic oscillator Hamiltonian built out of commuting (unphysical yet covariantly transforming under SU(2)) position like observable. The existence of this critical point is shown to be a novel aspect in non-commutative harmonic oscillator, which is exploited to obtain the spectrum and the observable mass and angular frequency parameters of the physical oscillator-which is generically different from the bare parameters occurring in the Hamiltonian. Finally, we show that a Zeeman term in the Hamiltonian of non-commutative physical harmonic oscillator, is solely responsible for both SU(2) and time reversal symmetry breaking.

Equivalence Between the Eigenvalue Problem of Non-Commutative Harmonic Oscillators and Existence of Holomorphic Solutions of Heun Differential Equations, Eigenstates Degeneration, and the Rabi Model

The initial aim of the present paper is to provide a complete description for the eigenvalue problem of the non-commutative harmonic oscillator (NcHO), which is given by a two-by-two system of paritypreserving ordinary differential operator [19], in terms of Heun's ordinary differential equations, the second order Fuchsian differential equations with four regular singularities in a complex domain. This description has been achieved for odd eigenfunctions in Ochiai [16] nicely but missing for even eigenfunctions up to now. As a by-product of this study, using the monodromy representation of Heun's equation, we prove that the multiplicity of the eigenvalue of the NcHO is at most two. Moreover, we give a condition for the existence of

Non-Commutative Harmonic Oscillators and Related Problems

This paper is mainly meant to be a survey on the state-of-the-art of the understanding we have of a family of systems with polynomial coefficients, called non-commutative harmonic oscillators (NCHOs), that has shown itself to be very rich in structure. The study of this family has required, and is requiring, the study of problems arising from different parts of Mathematics, from spectral theory to the theory of modular forms, just to mention a few of them. On the side of new results, they will be concerned with the creation-annihilation relations for NCHOs and with Fredholm properties of operators belonging to certain global Weyl-Hormander classes, of which NCHOs are a particular case.

Spectral analysis of non-commutative harmonic oscillators: The lowest eigenvalue and no crossing

The lowest eigenvalue of non-commutative harmonic oscillators Q(α,β) (α>0, β>0, αβ>1) is studied. It is shown that Q(α,β) can be decomposed into four self-adjoint operators,Q(α,β)=⨁σ=±,p=1,2Qσp, and all the eigenvalues of each operator Qσp are simple. We show that the lowest eigenvalue of Q(α,β) is simple whenever α≠β. Furthermore a Jacobi matrix representation of Qσp is given and spectrum of Qσp is considered numerically.

Twisted Conformal Algebra and Quantum Statistics of Harmonic Oscillators

We consider noncommutative two-dimensional quantum harmonic oscillators and extend them to the case of twisted algebra. We obtained modified raising and lowering operators. Also we study statistical mechanics and thermodynamics and calculated partition function which yields the free energy of the system.

On the essential spectrum of certain non-commutative oscillators

We show here that the spectrum of the family of non-commutative harmonic oscillators \documentclass[12pt]{minimal}\begin{document}$Q_{(\alpha ,\beta )}^\mathrm{w}(x,D)$\end{document}Q(α,β)w(x,D) for \documentclass[12pt]{minimal}\begin{document}$\alpha ,\beta \in \mathbb {R}_+$\end{document}α,β∈R+ in the range αβ = 1 is [0, +∞) and is entirely essential spectrum. The previous existing results concern the case αβ > 1 (case in which \documentclass[12pt]{minimal}\begin{document}$Q_{(\alpha ,\beta )}^\mathrm{w}(x,D)$\end{document}Q(α,β)w(x,D) is globally elliptic with a discrete spectrum whose qualitative properties are being extensively studied), and ours therefore extend the picture to the range of parameters αβ ⩾ 1.