Spin supercurrent in the canted antiferromagnetic phase

Hama, Yusuke; Tsitsishvili, G.; Ezawa, Zyun F.

doi:10.1103/physrevb.87.104516

Cited by 6 publications

(16 citation statements)

References 35 publications

(40 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We present the derivation of the Dicke model by constructing the Hamiltonian H R for the NG mode and the interaction Hamiltonian H SR between the nuclear spin and the NG mode in the case of the CAF phase. To derive the Dicke model, we make a concise review of the effective Hamiltonian density for the ground state and the NG modes in bilayer QH systems [2,8,11]. We start with the discussion on the phase structure as well as the spin density configuration, and the associated NG modes at 2. n = Then we present the effective Hamiltonian density for the linear dispersive NG mode in the CAF phase.…”

Section: Resultsmentioning

confidence: 99%

“…with E k a linear dispersion relation for the NG mode. We present the explicit formulas of equations (9), (11), and (12) for the case of the CAF phase in appendix B: see equations (B4), (B7), and (B10), respectively.…”

Section: Electron Spin Configuration and Effective Hamiltonian For Thmentioning

confidence: 99%

“…The above situation may change when the nuclear spins interact coherently with low-energy excitation modes of electron spins such as Nambu-Goldstone (NG) modes. For instance, the NG modes appear in the canted antiferromagnetic (CAF) phase [4][5][6][7][8][9][10][11][12] due to the spontaneous breaking of the rotational U(1) symmetry. This phase is the most interesting one among the three phases of the total filling factor 2 n = bilayer QH systems: the ferromagnetic phase, the spin-singlet phase and the CAF phase.…”

Section: Introductionmentioning

confidence: 99%

“…set of the NG mode. The ground-state expectation values of these fields must be xWe refer the detailed derivation of the SU(4) isospins (A8) and the canonical commutation relation (A9) to[11].…”

mentioning

confidence: 99%

See 3 more Smart Citations

Dicke model for quantum Hall systems

et al. 2016

View full text Add to dashboard Cite

In GaAs quantum Hall (QH) systems, electrons are coupled with nuclear spins through the hyperfine interaction, which is normally not strong enough to change the dynamics of electrons and nuclear spins. The dynamics of the QH systems, however, may drastically change when the nuclear spins interact with low-energy collective excitation modes of the electron spins. We theoretically investigate the nuclear-electron spin interaction in the QH systems as hybrid quantum systems driven by the hyperfine interaction. In particular, we study the interaction between the nuclear spins and the Nambu-Goldstone (NG) mode with the linear dispersion relation associated with the U(1) spin rotational symmetry breaking. We show that such an interaction is described as nuclear spins collectively coupled to the NG mode, and can be effectively described by the Dicke model. Based on the model we suggest that various collective spin phenomena realized in quantum optical systems can also emerge in the QH systems.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Electron Spin Configuration and Effective Hamiltonian For Thmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Dicke model for quantum Hall systems

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Note that this Hamiltonian is consistent with the one when the graphene possesses the canted antiferromagnetic phase. 48,49 For the graphene-based normal-spin superconductor junction, the graphene is in the spin superconducting phase when x > 0 and is in the normal phase when x < 0. The Hamiltonian of the normal graphene at x < 0 is…”

mentioning

confidence: 99%

Spin-flip reflection at the normal metal-spin superconductor interface

Guo

et al. 2017

Phys. Rev. B

View full text Add to dashboard Cite

We study spin transport through a normal metal-spin superconductor junction. A spin-flip reflection is demonstrated at the interface, where a spin-up electron incident from the normal metal can be reflected as a spin-down electron and the spin 2 × /2 will be injected into the spin superconductor. When the (spin) voltage is smaller than the gap of the spin superconductor, the spin-flip reflection determines the transport properties of the junction. We consider both graphene-based (lineardispersion-relation) and quadratic-dispersion-relation normal metal-spin superconductor junctions in detail. For the two-dimensional graphene-based junction, the spin-flip reflected electron can be along the specular direction (retro-direction) when the incident and reflected electron locates in the same band (different bands). A perfect spin-flip reflection can occur when the incident electron is normal to the interface, and the reflection coefficient is slightly suppressed for the oblique incident case. As a comparison, for the one-dimensional quadratic-dispersion-relation junction, the spin-flip reflection coefficient can reach 1 at certain incident energies. In addition, both the charge current and the spin current under a charge (spin) voltage are studied. The spin conductance is proportional to the spin-flip reflection coefficient when the spin voltage is less than the gap of the spin superconductor. These results will help us get a better understanding of spin transport through the normal metal-spin superconductor junction.

show abstract

Interlayer coherence and entanglement in bilayer quantum Hall states at filling factorν= 2/λ

Calixto

Pérez-Romero

2014

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We study coherence and entanglement properties of the state space of a composite bi-fermion (two electrons pierced by λ magnetic flux lines) at one Landau site of a bilayer quantum Hall system. In particular, interlayer imbalance and entanglement (and its fluctuations) are analyzed for a set of U (4) coherent (quasiclassical ) states generalizing the standard pseudospin U (2) coherent states for the spin-frozen case. The interplay between spin and pseudospin degrees of freedom opens new possibilities with regard to the spin-frozen case. Actually, spin degrees of freedom make interlayer entanglement more effective and robust under perturbations than in the spin-frozen situation, mainly for a large number of flux quanta λ. Interlayer entanglement of an equilibrium thermal state and its dependence with temperature and bias voltage is also studied for a pseudo-Zeeman interaction.

show abstract

Spin supercurrent in the canted antiferromagnetic phase

Cited by 6 publications

References 35 publications

Dicke model for quantum Hall systems

Dicke model for quantum Hall systems

Spin-flip reflection at the normal metal-spin superconductor interface

Interlayer coherence and entanglement in bilayer quantum Hall states at filling factorν= 2/λ

Contact Info

Product

Resources

About