Kondo Impurities Coupled to a Helical Luttinger Liquid: RKKY-Kondo Physics Revisited

Yevtushenko, O. M.; Yudson, V. I.

doi:10.1103/physrevlett.120.147201

Cited by 37 publications

(24 citation statements)

References 59 publications

(88 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The question of the effect of magnetic impurities on the conductance along helical edges was the subject of theoretical attention as well, considering different forms of impurities, coupling, and electronic band structures [35][36][37][38][39][40][41][42][43][44][45][46][47]. At low temperatures and in the absence of strong electron-electron interactions, a generic magnetic impurity forms a Kondo singlet and is screened out, allowing the helical edge to reconstitute itself around it and, therefore, has no effect on the conductance.…”

Section: Introductionmentioning

confidence: 99%

Analytical and numerical study of the out-of-equilibrium current through a helical edge coupled to a magnetic impurity

2020

View full text Add to dashboard Cite

We study the conductance of a time-reversal symmetric helical electronic edge coupled antiferromagnetically to a magnetic impurity, employing analytical and numerical approaches. The impurity can reduce the perfect conductance G0 of a noninteracting helical edge by generating a backscattered current. The backscattered steady-state current tends to vanish below the Kondo temperature TK for time-reversal symmetric setups. We show that the central role in maintaining the perfect conductance is played by a global U (1) symmetry. This symmetry can be broken by an anisotropic exchange coupling of the helical modes to the local impurity. Such anisotropy, in general, dynamically vanishes during the renormalization group (RG) flow to the strong coupling limit at low-temperatures. The role of the anisotropic exchange coupling is further studied using the time-dependent Numerical Renormalization Group (TD-NRG) method, uniquely suitable for calculating out-of-equilibrium observables of strongly correlated setups. We investigate the role of finite bias voltage and temperature in cutting the RG flow before the isotropic strong-coupling fixed point is reached, extract the relevant energy scales and the manner in which the crossover from the weakly interacting regime to the strong-coupling backscattering-free screened regime is manifested. Most notably, we find that at low temperatures the linear conductance of the backscattering current follows a power-law behavior G ∼ (T /TK ) 2 , and the strong exponent implies that the anisotopry might be a dominant cause for reducing the perfect edge conductance. arXiv:1912.02838v1 [cond-mat.str-el] 5 Dec 2019 Q S H I Impurity site t J I B e/(G 0 Γ) (b) J yy /Γ =1 J yy /Γ =0.7 J yy /Γ =0.5 J yy /Γ =0.3 J yy /Γ =0.1 0.0 0.2 0.4 0.6 0.8 1.0 J yy /Γ T eq K eG/(G 0 Γ) ·10 3(a) J yy /Γ =0.9 J yy /Γ =0.7 J yy /Γ =0.5 J yy /Γ =0.3 J yy /Γ =0.1

show abstract

Section: Introductionmentioning

confidence: 99%

Analytical and numerical study of the out-of-equilibrium current through a helical edge coupled to a magnetic impurity

2020

View full text Add to dashboard Cite

show abstract

“…The Kondo effects can dominate in the 1D KL only under some specific conditions, e.g. for small concentrations of local moments, strongly broken SU(2) spinrotation symmetry and strong Coulomb interactions [39] or strongly enlarged symmetry (SU(N ) instead of SU (2) with N 1) [16]. The surest indication of the RKKY-dominated physics is that it is insensitive to the sign of J K but, at the same time, is very sensitive to doping and anisotropy of the Kondo coupling.…”

Section: Introductionmentioning

confidence: 99%

Physics of arbitrarily doped Kondo lattices: From a commensurate insulator to a heavy Luttinger liquid and a protected helical metal

Tsvelik

Yevtushenko

2019

Phys. Rev. B

View full text Add to dashboard Cite

We study one-dimensional Kondo Lattices (KL) which consist of itinerant electrons interacting with Kondo impurities (KI) -localized quantum magnetic moments. We focus on KL with isotropic exchange interaction between electrons and KI and with a high KI density. The latter determines the principal róle of the indirect interaction between KI for the low energy physics. Namely, the Kondo physics becomes suppressed and all properties are governed by spin ordering. We present a first-ever comprehensive analytical theory of such KL at an arbitrary doping and predict a variety of regimes with different electronic phases. They range from commensurate insulators (at filling factors 1/2, 1/4 and 3/4) to metals with strongly interacting conduction electrons (close to these three special cases) to an exotic phase of a helical metal. The helical metals can provide a unique platform for realization of an emergent protection of ballistic transport in quantum wires. We compare out theory with previously obtained numerical results and discuss possible experiments where the theory could be tested.

show abstract

“…For the usual case at (or near) half-filling, the RKKY interaction has a magnitude oscillation at nesting wave vector due to the non-analytical susceptibility, but this phenomenon vanishes when away from the half-filling. Furthermore, for the helical Luttinger liquid, which can be realized by, e.g., the quantum spin Hall edge state [1], the spin rotation during the back scattering would eliminates the oscillation at nesting wave vector [2]. and the kondo screening is dominates over the RKKY interaction at large distance (between magnetic impurities) for such special Luttinger liquid.…”

Section: Introductionmentioning

confidence: 99%

Dynamical current–current correlation in two-dimensional parabolic Dirac systems

2019

Physics Letters A

View full text Add to dashboard Cite

Kondo Impurities Coupled to a Helical Luttinger Liquid: RKKY-Kondo Physics Revisited

Cited by 37 publications

References 59 publications

Analytical and numerical study of the out-of-equilibrium current through a helical edge coupled to a magnetic impurity

Analytical and numerical study of the out-of-equilibrium current through a helical edge coupled to a magnetic impurity

Physics of arbitrarily doped Kondo lattices: From a commensurate insulator to a heavy Luttinger liquid and a protected helical metal

Dynamical current–current correlation in two-dimensional parabolic Dirac systems

Contact Info

Product

Resources

About