arXiv subjects

Mariano J. Salvay

Publications and source records attributed to Mariano J. Salvay.

8 recordsLinked to original sources

arXiv2010

Transient effects in the backscattered current of a Luttinger liquid

We study the backscattered current in a Luttinger liquid in the presence of a point like weak impurity switched on at finite time, taking into account finite-temperature effects. We show how the well-known results for a static impurity are distorted. We derive a dimensionless parameter $τ_{R}$ as function of the electron-electron interaction and the temperature, such that for $τ_{R} < 1$ ($> 1$) the switching process is relevant (irrelevant). Our results suggest the possibility of determining the value of the Luttinger parameter $K$ through time measurements in transport experiments at fixed voltage.

cond-mat.str-el↗

arXiv2009

Pumping current and conductance of a Luttinger liquid in the presence of two time-dependent impurities at finite temperature

We study the pumping current and the conductance in a Tomonaga-Luttinger liquid in the presence of two time-dependent point like weak impurities, taking into account finite-temperature effects. We investigate the different regimes which can be established as function of the frequency, the temperature and the separation between the impurity potentials. We show how the previous zero temperature or single impurity results are distorted.

cond-mat.str-el↗

arXiv2006

Backscattering off a dynamical impurity in one-dimensional Fermi systems: A perturbative computation

We investigate the problem of backscattering off a time-dependent and spatially extended barrier in a one-dimensional electron gas. By performing a perturbative expansion in the backscattering amplitude, we compute the total energy density of the system. We show how the free fermion spectrum and the conductance of the system are affected by the interplay between dynamical and geometrical properties of the impurity.

cond-mat.other↗

arXiv2005

Conformal properties of 1D quantum systems with long-range interactions

We investigate conformal properties of a one-dimensional quantum system with a long-range, Coulomb-like potential of the form $\frac{1}{|x|^σ}$, with $σ>0$. We compute the conformal anomaly $c$ as function of $σ$. We obtain $c=0$ for $σ<1$ (Wigner crystal) and $c=1$ for $σ>1$ (Luttinger liquid). By studying the scaling regime of the system when it is deformed by the inclusion of a term $t ρ(x)$, (with $ρ(x)$ a scaling operator), we show that, for $σ>1$, the correlation length $ξ$ gets an additional interaction dependent factor. This leads to a necessary redefinition of $ξ$ in order to avoid an unphysical dependence of the central charge on the coupling constant.

cond-mat.str-el↗

arXiv2005

Non-perturbative approach to backscattering off a dynamical impurity in 1D Fermi systems

We investigate the problem of backscattering off a time-dependent impurity in a one-dimensional electron gas. By combining the Schwinger-Keldysh method with an adiabatic approximation in order to deal with the corresponding out of equilibrium Dirac equation, we compute the total energy density (TED) of the system. We show how the free fermion TED is distorted by the backscattering amplitude and the geometry of the impurity.

cond-mat.mes-hall↗

arXiv2004

Effect of nonadiabatic switching of dynamic perturbations in 1d Fermi systems

We study a two-dimensional fermionic QFT used to model 1D strongly correlated electrons in the presence of a time-dependent impurity that drives the system out of equilibrium. In contrast to previous investigations, we consider a dynamic barrier switched on at a finite time. We compute the total energy density (TED) of the system and establish two well defined regimes in terms of the relationship between the frequency of the time-dependent perturbation $Ω$ and the electron energy $ω$. Finally, we derive a relaxation time $t_{R}$ such that for times shorter than $t_{R}$ the finite-time switching process is relevant.

cond-mat.str-el↗

arXiv2003

Functional bosonization with time dependent perturbations

We extend a path-integral approach to bosonization previously developed in the framework of equilibrium Quantum Field Theories, to the case in which time-dependent interactions are taken into account. In particular we consider a non covariant version of the Thirring model in the presence of a dynamic barrier at zero temperature. By using the Closed Time Path (Schwinger-Keldysh) formalism, we compute the Green's function and the Total Energy Density of the system. Since our model contains the Tomonaga Luttinger model as a particular case, we make contact with recent results on non-equilibrium electronic systems.

hep-th↗

arXiv2003

RG study of a non local sine-Gordon model

We study a non local version of the sine-Gordon model connected to a many-body system with backward and umklapp scattering processes. Using renormalization group methods we derive the flow equations for the couplings and show how non locality affects the gap in the spectrum of charge-density excitations. We compare our results with previous predictions obtained through the self-consistent harmonic approximation.

hep-th↗