We study the phase diagram of a superconducting ring threaded by an Aharonov-Bohm flux and an in-plane magnetic Zeeman field. The simultaneous presence of both the external flux and the in-plane...
Tao, Jianmin, Tretiak, Sergei, Zhu, Jian-Xin
Excitation energies of light-emitting organic conjugated polymers have been investigated with time-dependent density functional theory (TDDFT) within the adiabatic approximation for the dynamical...
Vortex core states in a minimal two-band model for iron-based superconductors (2009)
Hu, Xiang, Ting, C. S., Zhu, Jian-Xin
The pairing symmetry is one of the major issues in the study of iron-based superconductors. We adopt a minimal two-band tight-binding model with various channels of pairing interaction, and derive a...
Impurity effect as a probe for $s_{x^2y^2}$ symmetry in iron-based superconductors (2009)
Zhou, Tao, Hu, Xiang, Zhu, Jian-Xin, Ting, C. S.
The spatially resolved impurity scattering is studied for a superconductor with $s_{x^2y^2}$ pairing symmetries based on a minimal two band model proposed by S. Raghu $et$ $al.$ [Phys. Rev. B {\bf...
Dai, Jianhui, Zhu, Jian-Xin, Si, Qimiao
Some of the high Tc iron pnictides contain rare-earth elements, raising the question of how the existence and tunability of a d-electron antiferromagnetic order influences the heavy fermion behavior...
Correlation effects in the iron pnictides (2009)
Si, Qimiao, Abrahams, Elihu, Dai, Jianhui, Zhu, Jian-Xin
One of the central questions about the iron pnictides concerns the extent to which their electrons are strongly correlated. Here we address this issue through the phenomenology of the charge...
Validity of Equation-of-Motion Approach to Kondo Problem in the Large-$N$ limit (2008)
Qi, Yunong, Zhu, Jian-Xin, Ting, C. S.
The Anderson impurity model for Kondo problem is investigated for arbitrary orbit-spin degeneracy $N$ of the magnetic impurity by the equation of motion method (EOM). By employing a new decoupling...
Iron pnictides as a new setting for quantum criticality (2008)
Dai, Jianhui, Si, Qimiao, Zhu, Jian-Xin, Abrahams, Elihu
Two major themes in the physics of condensed matter are quantum critical phenomena and unconventional superconductivity. These usually occur in the context of competing interactions in systems of...
Zhu, Jian-Xin, Chia, Elbert E. M., Tamegai, T., Eisaki, H., Oh, Kyu-Hwan, ...
Using ultrafast optical techniques, we probe the hole-doping dependence of the electron-boson coupling constant $\lambda$ in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$. In the overdoped region, we...
The magnetic flux dependence of order parameter and supercurrent is studied in a hollow d-wave superconducting cylinder. It is shown that the existence of line nodal quasiparticles in a pure...
Vibrational coherence in electron spin resonance in nanoscale oscillators (2008)
We study a scheme for electrical detection, using electron spin resonance, of coherent vibrations in a molecular single electron level trapped near a conduction channel. Both equilibrium...
Optimization of the design of superconducting inhomogeneous nanowires (2008)
Grigorenko, Ilya, Zhu, Jian-Xin, Balatsky, Alexander
We study optimization of superconducting properties of inhomogeneous nanowires. The main goal of this research is to find an optimized geometry that allows one to maximize the desired property of...
Impurity Quantum Phase Transition in a Current-Carrying d-Wave Superconductor (2008)
Wu, Yezheng, Yang, Shuxiang, Dai, Jianhui, Zhu, Jian-Xin
We study an Anderson impurity embedded in a d-wave superconductor carrying a non-zero momentum of Cooper pairs driven by magnetic flux through the Aharonov-Bohm effect. The zero-temperature impurity...
Kondo Stripes in an Anderson-Heisenberg Model of Heavy Fermion Systems (2008)
Zhu, Jian-Xin, Martin, I., Bishop, A. R.
We study the interplay between the spin-liquid and Kondo physics, as related to the non-magnetic part of the phase diagram of heavy fermion materials. Within the unrestricted mean-field treatment of...
Coulomb correlation in presence of spin-orbit coupling: application to plutonium (2007)
Julien, Jean-Pierre, Zhu, Jian-Xin, Albers, Robert C.
Attempts to go beyond the local density approximation (LDA) of Density Functional Theory (DFT) have been increasingly based on the incorporation of more realistic Coulomb interactions. In their...
Performance of a non-empirical meta-GGA density functional for excitation energies (2007)
Tao, Jianmin, Tretiak, Sergei, Zhu, Jian-Xin
It is known that the adiabatic approximation in time-dependent density functional theory usually provides a good description of low-lying excitations of molecules. In the present work, the capability...
Kondo Resonance in the Presence of Spin-Polarized Currents (2007)
Qi, Yunong, Zhu, Jian-Xin, Zhang, Shufeng, Ting, C. S.
We propose an improved method of the equation of motion approach to study the Kondo problem in spin-dependent non-equilibrium conditions. We find that the previously introduced additional...
Tuning impurity states in bilayer graphene (2007)
Dahal, Hari P., Balatsky, A. V., Zhu, Jian-Xin
We study the impurity states in bilayer graphene in the unitary limit using Green's function method. Unlike in single layer graphene, the presence of impurities at two non-equivalent sites in bilayer...
Wigner crystallization in a single and bilayer graphene (2007)
Dahal, Hari P., Wehling, Tim O., Bedell, Kevin S., Zhu, Jian-Xin, Balatsky, A. V.
We study the possibility of Wigner crystallization in both single- and and bi-layer graphene using a real space tight binding model. In addition to verifying our earlier prediction for single layer...
Chia, Elbert E. M., Zhu, Jian-Xin, Talbayev, D., Averitt, R. D., Oh, Kyu-Hwan, Jo, In-Sun, ...
We present studies of the photoexcited quasiparticle dynamics in Tl$_{2}$Ba$_{2}$Ca$_{2}$Cu$_{3}$O$_{y}$ (Tl-2223) using femtosecond optical techniques. Deep into the superconducting state (below 40...
Spectral Properties of delta-Plutonium: Sensitivity to 5f Occupancy (2007)
Zhu, Jian-Xin, McMahan, A. K., Jones, M. D., Durakiewicz, T., Joyce, J. J., Wills, J. M., ...
By combining the local density approximation (LDA) with dynamical mean field theory (DMFT), we report a systematic analysis of the spectral properties of $\delta$-plutonium with varying $5f$...
Time-Resolved Quasiparticle Dynamics in the Spin-Density-Wave State (2006)
Chia, Elbert E. M., Zhu, Jian-Xin, Lee, H. J., Hur, Namjung, Moreno, N. O., Averitt, R. D., ...
Time-resolved photoinduced reflectivity is measured in the spin-density-wave (SDW) phase using itinerant antiferromagnets UMGa$_{5}$ (M=Ni, Pt). For UNiGa$_{5}$ [$T_{N}$=85 K,...
Spin Dynamics in a Tunnel Junction between Ferromagnets (2006)
The dynamics of a single spin embedded in the tunnel junction (quantum point contact) between ferromagnets is addressed. Using the Keldysh technique, we derive a quantum Langevin equation. As a...
Zero-Temperature Magnetic Transition in an Easy-Axis Kondo Lattice Model (2006)
Zhu, Jian-Xin, Kirchner, Stefan, Bulla, Ralf, Si, Qimiao
We address the quantum transition of a spin-1/2 antiferromagnetic Kondo lattice model with an easy-axis anisotropy using the extended dynamical mean field theory. We derive results in real frequency...
Local Strong Coupling Pairing in $D$-Wave Superconductor with Inhomogeneous Bosonic Modes (2006)
Balatsky, A. V., Zhu, Jian-Xin
Recent local tunneling data indicate strong nanoscale inhomogeneity of superconducting gap in high temperature superconductors. Strong local nanoscale inhomogeneity in the bosonic scattering mode has...
Spin and spin-wave dynamics in Josephson junctions (2005)
Nussinov, Z., Shnirman, A., Arovas, D. P., Balatsky, A. V., Zhu, Jian-Xin
Dopant-Induced Local Pairing Inhomogeneity in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (2005)
A new theoretical model is presented to study the nanoscale electronic inhomogeneity in high-$T_c$ cuprates. In this model, we argue that the randomly distributed out-of-plane interstitial oxygen...
Zhu, Jian-Xin, McElroy, K., Lee, J., Devereaux, T. P., Si, Qimiao, Davis, J. C., ...
We study the $\tau_1$-impurity induced $\mathbf{q}$-space pattern of the energy derivative local density of states (LDOS) in a d-wave superconductor. We are motivated in part by the recent scanning...
Zhu, Jian-Xin, Balatsky, A. V., Devereaux, T. P., Si, Qimiao, Lee, J., McElroy, K., ...
We analyze the effects of the electronic coupling to bosonic modes in a d-wave superconductor. The role of the scattering due to boson on the momentum transfer between electronic states in the...
Magnetic Quantum Phase Transitions in Kondo Lattices (2005)
Si, Qimiao, Zhu, Jian-Xin, Grempel, D. R.
The identification of magnetic quantum critical points in heavy fermion metals has provided an ideal setting for experimentally studying quantum criticality. Motivated by these experiments,...
Competing Orderings in an Extended Falicov-Kimball Model (2005)
Brydon, P. M. R., Zhu, Jian-Xin, Gulacsi, M., Bishop, A. R.
We present a Hartree-Fock study of the Falicov-Kimball model extended by both on-site and non-local hybridization. We examine the interplay between excitonic effects and the charge-density wave (CDW)...
Spin and Spin-Wave Dynamics in Josephson Junctions (2004)
Nussinov, Zohar, Shnirman, Alexander, Arovas, Daniel P., Balatsky, Alexander V., Zhu, Jian-Xin
We extend the Keldysh formulation to quantum spin systems and derive exact equations of motion. This allows us to explore the dynamics of single spins and of ferromagnets when these are inserted...
Impurity-induced states in conventional and unconventional superconductors (2004)
Balatsky, A. V., Vekhter, I., Zhu, Jian-Xin
We review recent developments in our understanding of how impurities influence the electronic states in the bulk of superconductors. Our focus is on the quasi-localized states in the vicinity of...
Equation-of-Motion Approach to Dynamical Mean Field Theory (2004)
Zhu, Jian-Xin, Albers, R. C., Wills, J. M.
We propose using an equation-of-motion approach as an impurity solver for dynamical mean field theory. As an illustration of this technique, we consider a finite-$U$ Hubbard model defined on the...
Detecting Breather Excitations with Inelastic Tunneling Spectroscopy (2004)
Zhu, Jian-Xin, Rasmussen, K. O., Bishop, A. R., Balatsky, A. V.
We propose inelastic electron tunneling spectroscopy scanning tunneling microscopy (IETS-STM) as a means of exciting and observing intrinsic localized modes (breathers) in a macromolecule. As a...
Spin and Current Variations in Josephson Junctions (2004)
Shnirman, A., Nussinov, Z., Zhu, Jian-Xin, Balatsky, A. V., Makhlin, Yu.
We study the dynamics of a single spin embedded in the tunneling barrier between two superconductors. As a consequence of pair correlations in the superconducting state, the spin displays rich and...
Atomic scale elastic textures coupled to electrons in superconductors (2003)
Ahn, K. H., Zhu, Jian-Xin, Nussinov, Z., Lookman, T., Saxena, A., Balatsky, A. V., ...
We present an atomic scale theory of lattice distortions using strain related variables and their constraint equations. Our approach connects constrained atomic length scale variations to continuum...
Novel Spin Dynamics in a Josephson Junction (2003)
Zhu, Jian-Xin, Nussinov, Zohar, Shnirman, Alexander, Balatsky, Alexander V.
We address the dynamics of a single spin embedded in the tunneling barrier between two superconductors. As a consequence of pair correlations in the superconducting state, the spin displays a rich...
Vortex Core Excitations in Superconductors with Frustrated Antiferromagnetism (2003)
Zhu, Jian-Xin, Balatsky, A. V.
Motivated by recent discovery of cobalt oxide and organic superconductors, we apply an effective model with strong antiferromagnetic and superconducting pairing interaction to a related lattice...
Vibration Mode Induced Shapiro Steps and Backaction in Josephson Junctions (2003)
Zhu, Jian-Xin, Nussinov, Z., Balatsky, A. V.
A model of a superconducting tunnel junction coupled to a mechanical oscillator is studied at zero temperature in the case of linear coupling between the oscillator and tunneling electrons. It is...
Elasticity-Driven Nanoscale Electronic Structure in Superconductors (2003)
Zhu, Jian-Xin, Ahn, K. H., Nussinov, Z., Lookman, T., Balatsky, A. V., Bishop, A. R.
The effects of long-range anisotropic elastic deformations on electronic structure in superconductors are analyzed within the framework of the Bogoliubov-de Gennes equations. Cases of twin boundaries...
Continuous quantum phase transition in a Kondo lattice model (2003)
Zhu, Jian-Xin, Grempel, D. R., Si, Qimiao
We study the magnetic quantum phase transition in an anisotropic Kondo lattice model. The dynamical competition between the RKKY and Kondo interactions is treated using an extended dynamic mean field...
Effects of a Collective Spin Resonance Mode on the STM Spectra of D-Wave Superconductors (2003)
Zhu, Jian-Xin, Sun, Jun, Si, Qimiao, Balatsky, A. V.
A high-energy spin resonance mode is known to exist in many high-temperature superconductors. Motivated by recent scanning tunneling microscopy (STM) experiments in superconducting...
Chen, Yan, Zhu, Jian-Xin, Ting, C. S.
Based on a model Hamiltonian with a d-wave pairing interaction and a competing antiferromagnetic interaction, we numerically study the site dependence of the nuclear spin resonance (NMR) relaxation...
Inelastic Tunneling Spectroscopy in a D-wave Superconductor (2002)
Balatsky, A. V., Abanov, Ar., Zhu, Jian-Xin
We propose a mechanism to use inelastic tunneling spectrosopy STM to detect a single spin in a d-wave superconductor and in a pseudogap state, based on a direct exchange coupling J between the...
Zhu, Jian-Xin, Balatsky, A. V.
Using the Keldysh nonequilibrium Green function technique, we study the current and shot noise spectroscopy of a single molecular quantum dot coupled to a local phonon mode. It is found that in the...
Vortex Charges in High Temperature Superconductors (2002)
Chen, Yan, Wang, Z. D., Zhu, Jian-Xin, Ting, C. S.
Based on an effective model Hamiltonian with competing antiferromagnetic (AF) and d-wave superconductivity (DSC) interactions, the vortex charge in high T_c superconductors is investigated by solving...
Josephson Current in the Presence of a Precessing Spin (2002)
Zhu, Jian-Xin, Balatsky, A. V.
The Josephson current in the presence of a precessing spin between various types of superconductors is studied. It is shown that the Josephson current flowing between two spin-singlet pairing...
Quantum Electronic Transport through a Precessing Spin (2002)
Zhu, Jian-Xin, Balatsky, A. V.
The conductance through a local nuclear spin precessing in a magnetic field is studied by using the equations-of-motion approach. The characteristics of the conductance is determined by the tunneling...
Quantum Nyquist Temperature Fluctuations (2002)
Balatsky, A. V., Zhu, Jian-Xin
We consider the temperature fluctuations of a small object. Classical fluctuations of the temperature have been considered for a long time. Using the Nyquist approach, we show that the temperature of...
Both the differential tunneling conductance and the surface local density of states (LDOS) of a [110]-oriented high-temperature superconductor in the pseudogap (PG) regime are studied theoretically....
Incommensurate Magnetism around Vortices and Impurities in High-$T_c$ Superconductors (2002)
Zhu, Jian-Xin, Martin, Ivar, Bishop, A. R.
By solving self-consistently an effective Hamiltonian including interactions for both antiferromagnetic spin-density wave (SDW) and d-wave superconducting (DSC) orderings, a comparison study is made...
Field induced d_x^2-y^2+id_xy state in d-density-wave metals (2001)
Zhu, Jian-Xin, Balatsky, A. V.
We argue that the d_{xy} component of the order parameter can be generated to form the d_x^2-y^2+id_xy-density wave state by the external magnetic field. The driving force for this transition is the...
Zhu, Jian-Xin, Ting, C. S., Balatsky, A. V.
The local quasiparticle spectra around the vortex core of a d-wave superconductor in the mixed state is studied by solving the lattice Bogoliubov-de Gennes equations self-consistently. It is shown...
C-axis Response of a High-T_{c} Superconductor with D-Density Wave Order (2001)
Kim, Wonkee, Zhu, Jian-Xin, Carbotte, J. P., Ting, C. S.
The microscopic origin of the pseudogap state which exists in the underdoped cuprates remains unknown. The $c$-axis properties in the pseudogap regime are particularly anomalous. We use a recently...
Zhu, Jian-Xin, Kim, Wonkee, Ting, C. S., Carbotte, J. P.
Recently Chakravarty {\em et al.} proposed an ordered $d$-density wave (DDW) state as an explanation of the pseudogap phase in underdoped high-temperature cuprates. We study the competition between...
The local density of states (LDOS) at one of the vortex lattice cores in a high Tc superconductor is studied by using a self-consistent mean field theory including interactions for both...
The local quasiparticle density of states around a unitary impurity with a Kondo-like magnetic moment induced at its nearest neighbors in a d-wave superconductor is studied within the slave-boson...
The Kondo effects of an Anderson impurity embedded into a d-wave superconductor is studied. Within the slave-boson mean-field approach, the derived Bogoliubov-de Gennes equations are solved via exact...
Quasiparticle Localization in Disordered d-Wave Superconductors (2000)
Zhu, Jian-Xin, Sheng, D. N., Ting, C. S.
An extensive numerical study is reported on disorder effect in two-dimensional d-wave superconductors with random impurities in the unitary limit. It is found that a sharp resonant peak shows up in...
Effect of unitary impurities in non-STM-types of tunneling in high-T_c superconductors (2000)
Zhu, Jian-Xin, Ting, C. S., Hu, Chia-Ren
Based on an extended Hubbard model, we present calculations of both the local (i.e., single-site) and spatially-averaged differential tunneling conductance in d-wave superconductors containing...
Superconductivity in Ferromagnetic RuSr_2GdCu_2O_8 (2000)
Zhu, Jian-Xin, Ting, C. S., Chu, C. W.
The phase diagram of temperature versus exchange field is obtained within a BCS model for d-wave superconductivity in CuO_2 layers which is coupled to ferromagnetic RuO_2 layers in RuSr_2GdCu_2O_8....
Kim, Wonkee, Zhu, Jian-Xin, Ting, C. S.
Based on the linearized Eilenberger equations, the upper critical field $(H_{c2})$ of mixed d- and s-wave superconductors has been microscopically studied with an emphasis on the competing effects of...
The proximity effect, quasiparticle transport, and local magnetic moment in ferromagnet--d-wave superconductor junctions with {110}-oriented interface are studied by solving self-consistently the...
Quasiparticle Resonant States Induced by a Unitary Impurity in a d-Wave Superconductor (1999)
Zhu, Jian-Xin, Lee, T. K., Ting, C. S., Hu, Chia-Ren
The quasiparticle resonant states around a single nonmagnetic impurity with unitary scattering in a d-wave superconductor is studied by solving the Bogoliubov-de Gennes equations based on a t-J...
The induction of an s-wave component in a d-wave superconductor is considered. Near the {110}-oriented edges of such a sample, the induced s-wave order parameter together with d-wave component forms...
Time-dependent Ginzburg-Landau equations for mixed d- and s-wave superconductors (1998)
Zhu, Jian-Xin, Kim, W., Ting, C. S., Hu, Chia-Ren
A set of coupled time-dependent Ginzburg-Landau equations (TDGL) for superconductors of mixed d- and s-wave symmetry are derived microscopically from the Gor'kov equations by using the analytical...
An Alternative Understanding of the Fractional Quantum Hall Effect (1995)
Wang, Z., Zhu, Jian-Xin, Wang, Yun
We show that, in the presence of a strong magnetic field, a two-dimensional interacting electron gas can effectively be described by a Hamiltonian of `free' hard-core anions subject to the magnetic...
An Alternative Understanding of the Fractional Quantum Hall Effect (1995)
Wang, Z., Zhu, Jian-Xin, Wang, Yun
We show that, in the presence of a strong magnetic field, a two-dimensional interacting electron gas can effectively be described by a Hamiltonian of `free' hard-core anions subject to the magnetic...
An Alternative Understanding of the Fractional Quantum Hall Effect (1995)
Wang, Z., Zhu, Jian-Xin, Wang, Yun
We show that, in the presence of a strong magnetic field, a two-dimensional interacting electron gas can effectively be described by a Hamiltonian of `free' hard-core anions subject to the magnetic...
Morphology and ontogeny of dendritic cells in rats at different development periods
Zhou, Yi-Jun, Gao, Juan, Yang, Hua-Mei, Zhu, Jian-Xin, Chen, Tong-Xin, He, Zhen-Juan
AIM: To study the morphology and ontogeny of dendritic cells of Peyer’s patches in rats at different development periods.
Iron pnictides as a new setting for quantum criticality
Dai, Jianhui, Si, Qimiao, Zhu, Jian-Xin, Abrahams, Elihu
Two major themes in the physics of condensed matter are quantum critical phenomena and unconventional superconductivity. These usually occur in the context of competing interactions in systems of...