arXiv subjects

Wellington da Cruz

Publications and source records attributed to Wellington da Cruz.

At least 19 recordsLinked to original sources

arXiv2004

Fractal sets of dual topological quantum numbers

The universality classes of the quantum Hall transitions are considered in terms of fractal sets of dual topological quantum numbers filling factors, labelled by a fractal or Hausdorff dimension defined into the interval $1 < h < 2$ and associated with fractal curves. We show that our approach to the fractional quantum Hall effect-FQHE is free of any empirical formula and this characteristic appears as a crucial insight for our understanding of the FQHE. According to our formulation, the FQHE gets a fractal structure from the connection between the filling factors and the Hausdoff dimension of the quantum paths of particles termed fractons which obey a fractal distribution function associated with a fractal von Neumann entropy. This way, the quantum Hall transitions satisfy some properties related to the Farey sequences of rational numbers and so our theoretical description of the FQHE establishes a connection between physics, fractal geometry and number theory. The FQHE as a convenient physical system for a possible prove of the Riemann hypothesis is suggested.

math-ph↗

arXiv2004

Entanglement measure for the universal classes of fractons

We introduce the notion of entanglement measure for the universal classes of fractons as an entanglement between ocuppation-numbers of fractons in the lowest Landau levels and the rest of the many-body system of particles. This definition came as an entropy of the probability distribution {\it à la} Shannon. Fractons are charge-flux systems classified in universal classes of particles or quasiparticles labelled by a fractal or Hausdorff dimension defined within the interval $1 < h < 2$ and associated with the fractal quantum curves of such objects. They carry rational or irrational values of spin and the spin-statistics connection takes place in this fractal approach to the fractional spin particles. We take into account the fractal von Neumann entropy associated with the fractal distribution function which each universal class of fractons satisfies. We consider the fractional quantum Hall effect-FQHE given that fractons can model Hall states. According to our formulation entanglement between occupaton-numbers in this context increases with the universality classes of the quantum Hall transitions considered as fractal sets of dual topological quantum numbers filling factors. We verify that the Hall states have stronger entanglement between ocuppation-numbers and so we can consider this resource for fracton quantum computing.

quant-ph↗

arXiv2004

Quantum phase transitions of fractons (a fractal scaling theory for the FQHE)

We consider the quantum phase transitions of fractons in correspondence with the quantum phase transitions of the fractional quantum Hall effect-FQHE. We have that the Hall states can be modelled by fractons, known as charge-flux systems which satisfy a fractal distribution function associated with a fractal von Neumann entropy. In our formulation, the universality classes of the fractional quantum Hall transitions, are considered as fractal sets of dual topological quantum numbers filling factors labelled by the Hausdorff dimension $h$ ($1 < h < 2$) of the quantum paths of fractons. In this way we have defined, associated to these universality classes, a scaling exponent as $κ=1/h$, such that when $h$ runs into its interval of definition, we obtain $ 1 \gtrsim κ\gtrsim 0.5 $. The behavior of this scaling exponent, topological in character, is in agreement with some experimental values claimed in the literature. Thus, according to our approach we have a fractal scaling theory for the FQHE which distinguishes diverse universality classes for the fractional quantum Hall transitions.

cond-mat.mes-hall↗

arXiv2004

A fractal-like structure for the fractional quantum Hall effect

We have pursued in the literature a fractal-like structure for the fractional quantum Halll effect-FQHE which consider the Hausdorff dimension associated with the quantum mechanics paths and the spin of the particles or quasiparticles termed fractons. These objects carry rational or irrational values of spin and satisfy a fractal distribution function associated with a fractal von Neumann entropy. We show that our approach offers {\it a rationale} for all FQHE data including possible filling factors suggested by some authors. Our formulation is free of any empirical formula and this characteristic appears as a foundational insight for this FQHE-phenomenon. The connection between a geometrical parameter, the Hausdorff dimension $h$, associated with the quantum paths and the spin $s$ of particles, $h=2-2s$, $0 < s < {1/2}$, is a physical analogous to the fractal dimension formula, $Δ(Γ)=2-H$, of the graph of the functions in the context of the fractal geometry, where $H$ is knwon as Hölder exponent, with $ 0 < H < 1$. We emphasize that our fractal approach to the fractional spin particles gives us a new perspective for charge-flux systems defined in two-dimensional multiply connected space.

cond-mat.mes-hall↗

arXiv2004

The spin-statistics connection, the Gauss-Bonnet theorem and the Hausdorff dimension of the quantum paths

We obtain an explicit expression relating the writhing number, $W[C]$, of the quantum path, $C$, with any value of spin, $s$, of the particle which sweeps out that closed curve. We consider a fractal approach to the fractional spin particles and, in this way, we make clear a deeper connection between the Gauss-Bonnet theorem with the spin-statistics relation via the concept of Hausdorff dimension, $h$, associated to the fractal quantum curves of the particles: \frac{h}{2+2s}=W[C]=\frac{1}{4π}\oint_{C}d x_α\oint_{C}d x_β ε^{αβγ} \frac{(x-y)_γ}{|x-y|^3}.

hep-th↗

arXiv2003

A quantum-geometrical description of the statistical laws of nature

We consider the fractal characteristic of the quantum mechanical paths and we obtain for any universal class of fractons labeled by the Hausdorff dimension defined within the interval 1$ $$ < $$ $$h$$ $$ <$$ $$ 2$, a fractal distribution function associated with a fractal von Neumann entropy. Fractons are charge-flux systems defined in two-dimensional multiply connected space and they carry rational or irrational values of spin. This formulation can be considered in the context of the fractional quantum Hall effect-FQHE, where we discovered that the quantization of the Hall resistance occurs in pairs of dual topological quantum numbers, the filling factors. In this way, these quantum numbers get their topological character from the Hausdorff dimension associated with the fractal quantum path of such particles termed fractons. On the other hand, the universality classes of the quantum Hall transitions can be classified in terms of $h$. Another consequence of our approach, which is supported by symmetry principles, is the prediction of the FQHE. The connection between Physics and Number Theory appears naturally in this context.

cond-mat.stat-mech↗

arXiv2003

The Hausdorff dimension of fractal sets and fractional quantum Hall effect

We consider Farey series of rational numbers in terms of {\it fractal sets} labeled by the Hausdorff dimension with values defined in the interval 1$ $$ < $$ $$h$$ $$ <$$ $$ 2$ and associated with fractal curves. Our results come from the observation that the fractional quantum Hall effect-FQHE occurs in pairs of {\it dual topological quantum numbers}, the filling factors. These quantum numbers obey some properties of the Farey series and so we obtain that {\it the universality classes of the quantum Hall transitions are classified in terms of $h$}. The connection between Number Theory and Physics appears naturally in this context.

math-ph↗

arXiv2003

On the dual topological quantum numbers filling factors

We consider recent experimental results [W. Pan {\it et al}, Phys. Rev. Lett. {\bf 90}, 016801 (2003)] for occurrence of the fractional quantum Hall effect-FQHE under the perspective of our formulation in terms of {\it fractons}. These objects carry rational or irrational values of spin and satisfy a {\it fractal distribution function} associated with a {\it fractal von Neumann entropy}. According to our approach the {\it FQHE occurs in pairs of dual topological quantum numbers fillings factors} and this geometrical character comes from the {\it connection betwenn the fractal parameter or Hausdorff dimension $h$ and the spin $s$ of the particles}. We suggest to the experimentalists consider our ideas and verify in fact that this phenomenon of FQHE satisfy a {\it symmetry principle} discovered by us, i.e, {\it the duality symmetry betwenn universal classes of fractons}.

cond-mat.mes-hall↗

arXiv2003

A quantum-geometrical description of fracton statistics

cond-mat.stat-mech↗

arXiv2002

Fractal distribution function and fractal-deformed Heisenberg algebras

We consider the concept of fractons, i.e. particles or quasiparticles which obey specific fractal distribution function and for each universal class h of particles we obtain a fractal-deformed Heisenberg algebra. This one takes into account the braid group structure of these objects which live in two-dimensional multiply connected space.

hep-th↗

arXiv2002

Fractal von Neumann entropy

We consider the {\it fractal von Neumann entropy} associated with the {\it fractal distribution function} and we obtain for some {\it universal classes h of fractons} their entropies. We obtain also for each of these classes a {\it fractal-deformed Heisenberg algebra}. This one takes into account the braid group structure of these objects which live in two-dimensional multiply connected space.

cond-mat.stat-mech↗

arXiv2001

Fractons and high-$T_{c}$ superconductivity

We consider the concept of fractons in the context of high-$T_{c}$ superconductivity. These objects, which carry rational or irrational quantum numbers, are classified into universal classes $h$ of particles or quasiparticles which obey specific fractal distribution function. We show that the relaxation time associated to Hall conductivity for the superconducting cuprate systems came to out as $τ_{H}\propto T^{-2}$. We also consider the pairing of fractons as a mechanism to produce bosonic systems and therefore superconducting states. For that an effective mass obtained from the propagator of a charge-flux system is considered. In this way, some experimental results of infrared studies of the cuprates for the effective mass, $m^*=m_{e}(1+λ)$, compared with our effective mass expression, $m_{eff}=m(1+s)$, show us that the dominant factor for interactions came from the spin. Thus spin flutuactions as a mechanism of high-$T_{c}$ superconductivity and fractons as quasiparticles are related. An expression to the low temperature specific heat of a quantum liquid of fractons is also obtained.

cond-mat.str-el↗

arXiv2000

Fractal Statistics and Quantum Black Hole Entropy

Simple considerations about the fractal characteristic of the quantum-mechanical path give us the opportunity to derive the quantum black hole entropy in connection with the concept of fractal statistics. We show the geometrical origin of the numerical factor of four of the quantum black hole entropy expression and the statistics weight appears as a counting of the quanta of geometry.

hep-th↗

arXiv2000

Fractal statistics, fractal index and fractons

The concept of fractal index is introduced in connection with the idea of universal class $h$ of particles or quasiparticles, termed fractons, which obey fractal statistics. We show the relation between fractons and conformal field theory(CFT)-quasiparticles taking into account the central charge $c[ν]$ and the particle-hole duality $ν\longleftrightarrow\frac{1}ν$, for integer-value $ν$ of the statistical parameter. The Hausdorff dimension $h$ which labelled the universal classes of particles and the conformal anomaly are therefore related. We also establish a connection between Rogers dilogarithm function, Farey series of rational numbers and the Hausdorff dimension.

hep-th↗

arXiv2000

Fractal index, central charge and fractons

We introduce the notion of fractal index associated with the universal class $h$ of particles or quasiparticles, termed fractons, which obey specific fractal statistics. A connection between fractons and conformal field theory(CFT)-quasiparticles is established taking into account the central charge $c[ν]$ and the particle-hole duality $ν\longleftrightarrow\frac{1}ν$, for integer-value $ν$ of the statistical parameter. In this way, we derive the Fermi velocity in terms of the central charge as $v\sim\frac{c[ν]}{ν+1}$. The Hausdorff dimension $h$ which labelled the universal classes of particles and the conformal anomaly are therefore related. Following another route, we also established a connection between Rogers dilogarithm function, Farey series of rational numbers and the Hausdorff dimension.

hep-th↗

arXiv2000

Fractons and Luttinger liquids

We consider the concept of fractons as particles or quasiparticles which obey a specific fractal statistics in connection with a one-dimensional Luttinger liquid theory. We obtain a dual statistics parameter ${\tildeν}=ν+1$ which is identified with the controlling parameter $e^{-2ϕ}$ of the Luttinger model. In this way, a bosonic system characterized by a fractal index $i_{f}[h]=i_{f}[2]=1$ is considered as a conformal field theory with central charge $c[ν=0]=1=i_{f}[2]$ with a compactified radius $R=\frac{1}{\sqrt{\tildeν}}=1$. Thus, we have a mapping of a bosonic theory to a fermionic one and vice-versa, i.e., the duality symmetry ${\tilde{h} =3-h}$ of the universal class $h$ of fractons defined in the interval 1< h <2 is satisfied.

cond-mat.mes-hall↗

arXiv2000

Fractons and Fractal Statistics

Fractons are anyons classified into equivalence classes and they obey a specific fractal statistics. The equivalence classes are labeled by a fractal parameter or Hausdorff dimension $h$. We consider this approach in the context of the Fractional Quantum Hall Effect (FQHE) and the concept of duality between such classes, defined by $\tilde{h}=3-h$ shows us that the filling factors for which the FQHE were observed just appear into these classes. A connection between equivalence classes $h$ and the modular group for the quantum phase transitions of the FQHE is also obtained. A $β-$function is defined for a complex conductivity which embodies the classes $h$. The thermodynamics is also considered for a gas of fractons $(h,ν)$ with a constant density of states and an exact equation of state is obtained at low-temperature and low-density limits. We also prove that the Farey sequences for rational numbers can be expressed in terms of the equivalence classes $h$.

hep-th↗

arXiv2000

On Anyonic Propagators

We consider a simple action for a fractional spin particle and a path integral representation for the propagator is obtained in a gauge such that the constraint embodied in the Lagrangian is not an obstacle. We obtain a propagator for the particle in a constant electromagnetic field via the path integral representation over velocities, which is characterized by arbitrary boundary conditions and the absence of time derivatives following integration over bosonic variables.

hep-th↗