36 citations · 205 across the 15 of their papers we have counts for
15 papers
Quantum entanglement in a pure state of strongly correlated quantum impurity systems
Yunori Nishikawa, Tomoki Yoshioka
We consider quantum entanglement in strongly correlated quantum impurity systems for states manifesting interesting properties such as multi-level Kondo effect and dual nature betw…
Kondo effect in Lieb's ferrimagnetic system on the T-shaped bipartite lattice
Masashi Tokuda, Yunori Nishikawa
The minimal ferrimagnetism by Lieb's theorem emerges on the T-shaped bipartite lattice composed of four sites, which can be realized experimentally, just as Nagaoka ferromagnetism…
Current cross-correlation in the Anderson impurity model with exchange interaction
Rui Sakano, Akira Oguri, Yunori Nishikawa +1
We study spin-entanglement of the quasiparticles of the local Fermi liquid excited in nonlinear current through a quantum dot described by the Anderson impurity model with two dege…
Bell-state correlations in current of local Fermi liquid
Rui Sakano, Akira Oguri, Yunori Nishikawa +1
We study Bell-state correlations for quasiparticle pairs excited in nonlinear current through a double quantum dot in the Kondo regime. Exploiting the renormalized perturbation exp…
Magnetic field induced quantum criticality and the Luttinger sum rule
Y. Nishikawa, O. J. Curtin, A. C. Hewson +1
We show that when there is a sudden transition from a small to a large Fermi surface at a field-induced quantum critical point, similar to what may have been observed in some heavy…
Fermi Liquids and the Luttinger Integral
O. J. Curtin, Y. Nishikawa, A. C. Hewson +1
The Luttinger Theorem, which relates the electron density to the volume of the Fermi surface in an itinerant electron system, is taken to be one of the essential features of a Ferm…
Conditions for observing emergent SU(4) symmetry in a double quantum dot
Yunori Nishikawa, Oliver J. Curtin, Alex C. Hewson +2
We analyze conditions for the observation of a low energy SU(4) fixed point in capacitively coupled quantum dots. One problem, due to dots with different couplings to their baths,…
Analysis of low energy response and possible emergent SU(4) Kondo state in a double quantum dot
Yunori Nishikawa, Alex C. Hewson, Daniel J. G. Crow +1
We examine the low energy behavior of a double quantum dot in a regime where spin and pseudospin excitations are degenerate. The individual quantum dots are described by Anderson i…
Study of Hund's rule coupling in models of magnetic impurities and quantum dots
Y. Nishikawa, A. C. Hewson
Studies of the effects of the Hund's rule coupling J_H in multiple orbit impurities or quantum dots using different models have led to quite different predictions for the Kondo tem…
Phase diagram and critical points of a double quantum dot
Y. Nishikawa, D. J. G. Crow, A. C. Hewson
We apply a combination of numerical renormalization group (NRG) and renormalized perturbation theory (RPT) to a model of two quantum dots (impurities) described by two Anderson imp…
Full counting statistics for orbital-degenerate impurity Anderson model with Hund's rule exchange coupling
Rui Sakano, Yunori Nishikawa, Akira Oguri +2
We study non-equilibrium current fluctuations through a quantum dot, which includes a ferromagnetic Hund's rule coupling , in the low-energy Fermi liquid regime using the renorm…
Convergence of energy scales on the approach to a local quantum critical point
Y. Nishikawa, D. J. G. Crow, A. C. Hewson
We find the emergence of strong correlations and universality on the approach to the quantum critical points of a two impurity Anderson model. The two impurities are coupled by an…
Kondo effects in a triangular triple quantum dot with lower symmetries
A. Oguri, S. Amaha, Y. Nishikawa +4
The triangular triple quantum dot is an interesting system which can demonstrate various types of the Kondo effects, such as the one due to the local spin S=1 moment caused by the…
Renormalized parameters and perturbation theory for an n-channel Anderson model with Hund's rule coupling: Asymmetric case
Yunori Nishikawa, Daniel D. G. Crow, Alex C. Hewson
We explore the predictions of the renormalized perturbation theory for an n-channel Anderson model, both with and without Hund's rule coupling, in the regime away from particle-hol…
Renormalized parameters and perturbation theory for an n-channel Anderson model with Hund's rule coupling
Y Nishikawa, D J G Crow, A C Hewson
We extend the renormalized perturbation theory for the single impurity Anderson model to the n-channel model with a Hund's rule coupling, and show that the exact results for the sp…