Latha K V P | Pondicherry university (original) (raw)

Papers by Latha K V P

Arxiv preprint physics/ …, Jan 1, 2005

Electric quadrupole moment of the 4d 2 D 5/2 state in 88 Sr + and its role in an optical frequenc... more Electric quadrupole moment of the 4d 2 D 5/2 state in 88 Sr + and its role in an optical frequency standard

Physical Review B Condensed Matter And Materials …

Based on the recent paper [Phys. Rev. Lett. 102, 216803 (2009)], we study the nonequilibrium occu... more Based on the recent paper [Phys. Rev. Lett. 102, 216803 (2009)], we study the nonequilibrium occupation number n d and charge susceptibility χ of a resonance level close to dissipative quantum phase transition of the Kosterlitz-Thouless (KT) type between a delocalized phase for ...

Current topics in …, Jan 1, 2007

Arxiv preprint arXiv:0805.2723, Jan 1, 2008

We have developed an efficient tabulation scheme to evaluate 6j symbols for atomic calculations. ... more We have developed an efficient tabulation scheme to evaluate 6j symbols for atomic calculations. The scheme is appropriate for coupled-cluster based calculations. In particular, for perturbed coupled-clusters calculations, which has another perturbation in addition to the residual Coulomb interaction. The scheme relies on the symmetry of the 6j symbol and the triangular conditions.

Journal of Physics: …, Jan 1, 2007

A new formulation of the relativistic many-body theory of electric dipole moments of closed shell... more A new formulation of the relativistic many-body theory of electric dipole moments of closed shell atoms Abstract.

Physical Review A, Jan 1, 2007

Physical Review B, Jan 1, 2010

We theoretically investigate the non-equilibrium current through a quantum dot coupled to onedime... more We theoretically investigate the non-equilibrium current through a quantum dot coupled to onedimensional electron leads, utilizing a controlled frequency-dependent renormalization group (RG) approach. We compute the non-equilibrium conductance for large bias voltages and address the interplay between decoherence, Kondo entanglement and Luttinger physics. The combined effect of large bias voltage and strong interactions in the leads, known to stabilize two-channel Kondo physics, leads to non-trivial modifications of the conductance. For weak interactions, we build an analogy to a dot coupled to helical edge states of two-dimensional topological insulators. PACS numbers: 72.15.Qm, 7.23.-b, 03.65.Yz

Arxiv preprint physics/ …, Jan 1, 2005

Physical Review B, Jan 1, 2010

Based on the recent paper (Phys. Rev. Lett. 102, 216803, (2009)), we study the nonequilibrium occ... more Based on the recent paper (Phys. Rev. Lett. 102, 216803, (2009)), we study the nonequilibrium occupation number n d and charge susceptibility χ of a resonance level close to dissipative quantum phase transition of the Kosterlitz-Thouless (KT) type between a de-localized phase for weak dissipation and a localized phase for strong dissipation. The resonance level is coupled to two spinless fermionic baths with a finite bias voltage and an Ohmic bosonic bath representing the dissipative environment. The system is equivalent to an effective anisotropic Kondo model out of equilibrium. Within the nonequilibrium Renormalization Group (RG) approach, we calculate nonequilibrium magnetization M and spin susceptibility χ in the effective Kondo model, corresponding to 2n d − 1 and χ of a resonance level, respectively. We demonstrate the smearing of the KT transition in the nonequilibrium magnetization M as a function of the effective anisotropic Kondo couplings, in contrast to a perfect jump in M at the transition in equilibrium. In the limit of large bias voltages, we find M and χ at the KT transition and in the localized phase show deviations from the equilibrium Curie-law behavior. As the system gets deeper in the localized phase, both n d − 1/2 and χ decrease more rapidly to zero with increasing bias voltages.

Journal of Physics B: …, Jan 1, 2008

The effects of parity and time reversal violating potential, in particular the tensor-pseudotenso... more The effects of parity and time reversal violating potential, in particular the tensor-pseudotensor electron nucleus interaction are studied. We establish that selected terms representing the interplay of these effects and the residual Coulomb interaction in the coupled-cluster method are equivalent to the coupled perturbed Hartree-Fock. We have shown that the normal CPHF diagrams have a one-one correspondance in the coupled-cluster theory, but the CPHF pseudo diagrams are present in a subtle way. We have studied the pseudo diagrams in great detail and have shown explicitly their origin in coupled-cluster theory. This is demonstrated by considering the case of the permanent electric dipole moment of atomic Hg and our results are compared with the results of an earlier calculation.

Arxiv preprint physics/ …, Jan 1, 2005

Electric quadrupole moment of the 4d 2 D 5/2 state in 88 Sr + and its role in an optical frequenc... more Electric quadrupole moment of the 4d 2 D 5/2 state in 88 Sr + and its role in an optical frequency standard

Physical Review B Condensed Matter And Materials …

Based on the recent paper [Phys. Rev. Lett. 102, 216803 (2009)], we study the nonequilibrium occu... more Based on the recent paper [Phys. Rev. Lett. 102, 216803 (2009)], we study the nonequilibrium occupation number n d and charge susceptibility χ of a resonance level close to dissipative quantum phase transition of the Kosterlitz-Thouless (KT) type between a delocalized phase for ...

Current topics in …, Jan 1, 2007

Arxiv preprint arXiv:0805.2723, Jan 1, 2008

We have developed an efficient tabulation scheme to evaluate 6j symbols for atomic calculations. ... more We have developed an efficient tabulation scheme to evaluate 6j symbols for atomic calculations. The scheme is appropriate for coupled-cluster based calculations. In particular, for perturbed coupled-clusters calculations, which has another perturbation in addition to the residual Coulomb interaction. The scheme relies on the symmetry of the 6j symbol and the triangular conditions.

Journal of Physics: …, Jan 1, 2007

A new formulation of the relativistic many-body theory of electric dipole moments of closed shell... more A new formulation of the relativistic many-body theory of electric dipole moments of closed shell atoms Abstract.

Physical Review A, Jan 1, 2007

Physical Review B, Jan 1, 2010

We theoretically investigate the non-equilibrium current through a quantum dot coupled to onedime... more We theoretically investigate the non-equilibrium current through a quantum dot coupled to onedimensional electron leads, utilizing a controlled frequency-dependent renormalization group (RG) approach. We compute the non-equilibrium conductance for large bias voltages and address the interplay between decoherence, Kondo entanglement and Luttinger physics. The combined effect of large bias voltage and strong interactions in the leads, known to stabilize two-channel Kondo physics, leads to non-trivial modifications of the conductance. For weak interactions, we build an analogy to a dot coupled to helical edge states of two-dimensional topological insulators. PACS numbers: 72.15.Qm, 7.23.-b, 03.65.Yz

Arxiv preprint physics/ …, Jan 1, 2005

Physical Review B, Jan 1, 2010

Based on the recent paper (Phys. Rev. Lett. 102, 216803, (2009)), we study the nonequilibrium occ... more Based on the recent paper (Phys. Rev. Lett. 102, 216803, (2009)), we study the nonequilibrium occupation number n d and charge susceptibility χ of a resonance level close to dissipative quantum phase transition of the Kosterlitz-Thouless (KT) type between a de-localized phase for weak dissipation and a localized phase for strong dissipation. The resonance level is coupled to two spinless fermionic baths with a finite bias voltage and an Ohmic bosonic bath representing the dissipative environment. The system is equivalent to an effective anisotropic Kondo model out of equilibrium. Within the nonequilibrium Renormalization Group (RG) approach, we calculate nonequilibrium magnetization M and spin susceptibility χ in the effective Kondo model, corresponding to 2n d − 1 and χ of a resonance level, respectively. We demonstrate the smearing of the KT transition in the nonequilibrium magnetization M as a function of the effective anisotropic Kondo couplings, in contrast to a perfect jump in M at the transition in equilibrium. In the limit of large bias voltages, we find M and χ at the KT transition and in the localized phase show deviations from the equilibrium Curie-law behavior. As the system gets deeper in the localized phase, both n d − 1/2 and χ decrease more rapidly to zero with increasing bias voltages.

Journal of Physics B: …, Jan 1, 2008

The effects of parity and time reversal violating potential, in particular the tensor-pseudotenso... more The effects of parity and time reversal violating potential, in particular the tensor-pseudotensor electron nucleus interaction are studied. We establish that selected terms representing the interplay of these effects and the residual Coulomb interaction in the coupled-cluster method are equivalent to the coupled perturbed Hartree-Fock. We have shown that the normal CPHF diagrams have a one-one correspondance in the coupled-cluster theory, but the CPHF pseudo diagrams are present in a subtle way. We have studied the pseudo diagrams in great detail and have shown explicitly their origin in coupled-cluster theory. This is demonstrated by considering the case of the permanent electric dipole moment of atomic Hg and our results are compared with the results of an earlier calculation.