Intrinsic Damping of Collective Spin Modes in a Two-Dimensional Fermi Liquid with Spin-Orbit Coupling

Maiti, Saurabh; Maslov, Dmitrii L.

doi:10.1103/physrevlett.114.156803

Cited by 13 publications

(17 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Temperature dependence of (a) the intensity, (b) full width at half maximum (FWHM), and (c) peak center, of the chiral spin mode damping of chiral spin waves [21,45]. At higher temperatures, inelastic scattering mechanisms, e.g., electronelectron [45,66] or electron-phonon [67] interactions, may also contribute to damping.…”

Section: Fig S7mentioning

confidence: 99%

“…At higher temperatures, inelastic scattering mechanisms, e.g., electronelectron [45,66] or electron-phonon [67] interactions, may also contribute to damping. However, we found that a model, which incorporates the finite-temperature effects only via thermal smearing of the Fermi functions and neglects inelastic damping mechanisms, describes the experiment rather well.…”

Section: Fig S7mentioning

confidence: 99%

“…At q = 0, there is a doubly degenerate mode with an inplane magnetic moment and a transverse mode with an out-of-plane moment, with energies ω s,|| and ω s,⊥ , respectively. Because the chiral-spin modes are below the continuum, they are expected to remain long-lived even at elevated temperatures [45]. These modes are in essence (zero-field) spin waves that can be measured by resonant Raman scattering because they couple to the electromagnetic field through antisymmetric Raman tensors [25].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Chiral Spin Mode on the Surface of a Topological Insulator

et al. 2017

View full text Add to dashboard Cite

Using polarization-resolved resonant Raman spectroscopy, we explore collective spin excitations of the chiral surface states in a three dimensional topological insulator, Bi2Se3. We observe a sharp peak at 150 meV in the pseudovector A2 symmetry channel of the Raman spectra. By comparing the data with calculations, we identify this peak as the transverse collective spin mode of surface Dirac fermions. This mode, unlike a Dirac plasmon or a surface plasmon in the charge sector of excitations, is analogous to a spin wave in a partially polarized Fermi liquid, with spin-orbit coupling playing the role of an effective magnetic field.Magnets and partially spin-polarized Fermi liquids support collective spin excitations (spin waves), in which all electron spins respond coherently to external fields, and the "glue" that locks the phases of precessing spins is provided by the exchange interaction. In nonmagnetic materials where inversion symmetry is broken but time-reversal invariance remains intact, strong spin-orbit coupling (SOC) may play the role of an effective magnetic field, which locks electron spins and momenta into textures. This phenomenon is encountered in threedimensional (3D) topological insulators (TIs), which harbor topologically protected surface states [1][2][3][4][5]. These states have been a focus of intense studies, both from the fundamental point-of-view [6][7][8][9][10][11][12] and for potential applications in spintronics devices [13][14][15][16][17][18][19][20]. However, the many-body interactions leading to collective effects in TIs remain largely unexplored. An essential aspect of this physics is an interplay between the Coulomb interaction and SOC, which is expected to give rise to a new type of collective spin excitations -chiral spin waves [21][22][23][24][25][26]. In the long wavelength (q = 0) limit, these modes are completely decoupled from the charge channel and thus distinct from spin-plasmons [27,28], Dirac plasmons [29,30], and surface plasmons in TIs [30,31].In this Letter, we employ polarization-resolved resonant Raman spectroscopy, a technique of choice for probing the collective charge [32,33], spin [34][35][36][37] and orbital excitations [38], to study collective spin excitations of the chiral surface states in Bi 2 Se 3 . To enhance the signal from the surface states, we tune the energy of incoming photons in resonance with a transition between two sets of chiral surface states: near the Fermi energy and about 1.8 eV above it [ Fig. 1(a)] [39]. We observe a long-lived excitation at 150 meV in the pseudovector symmetry channel of the Raman spectra, which is most pronounced at low temperatures but persists up to room temperature. By comparing the data with calculations, we identify this excitation as the transverse collective chiral spin mode supported by spin-polarized surface Dirac fermions. Such collective modes -first predicted for nontopological systems [21][22][23][24][25][26]36] but hitherto unobserved -are "peeled off" from the continuum of particle-hole excitations by t...

show abstract

Section: Fig S7mentioning

confidence: 99%

Section: Fig S7mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Chiral Spin Mode on the Surface of a Topological Insulator

et al. 2017

View full text Add to dashboard Cite

show abstract

“…17,18 SO coupling was predicted to deeply modify the nature of these excitations, leading to chiral collective modes. [19][20][21] Conversely, it was shown that Coulomb interaction can induce a striking organization of the SO fields acting on a spin wave. [22][23][24][25] Indeed, for the two main kinds of collective spin modes of quantum wells (intra-and inter-subband), Coulomb interaction transforms the D'yakonov-Perel' decoherence scenario into a constructive scenario, where the spin dynamics is governed by a collective SO field B coll SO (q).…”

Section: Introductionmentioning

confidence: 99%

Electron density magnification of the collective spin-orbit field in quantum wells

et al. 2015

View full text Add to dashboard Cite

The spin-orbit field acting on the spin waves of a spin-polarized electron gas is studied by inelastic light scattering on a CdMnTe quantum well. Above-barrier illumination allows us to vary the electronic density and control the collective Rashba and Dresselhaus coupling constants. We demonstrate that the enhancement between the single-particle and the collective spin-orbit field increases with increasing electronic density. This result is reproduced by a first-principles calculation. This behavior, which is opposite to usual Coulombic spin enhancements, reveals a novel aspect of the interplay of spin-orbit and Coulomb interactions in collective spin modes.

show abstract

“…In a related study [85], the intrinsic linewidth of the chiral spin waves due to the interplay of SOC and momentum exchange between '+' and '−' spin populations (transversal SCD) was analyzed using diagrammatic expansion techniques. It was shown that, because of SOC, dissipation due to transverse SCD -usually vanishing as q → 0 -remains non-zero even at q = 0.…”

Section: Chiral Spin Wavesmentioning

confidence: 99%

Chirality and intrinsic dissipation of spin modes in two-dimensional electron liquids

D’Amico

Pérez

Ullrich

2019

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

We review recent theoretical and experimental developments concerning collective spin excitations in two-dimensional electron liquid (2DEL) systems, with particular emphasis on the interplay between many-body and spin-orbit effects, as well as the intrinsic dissipation due to the spin-Coulomb drag. Historically, the experimental realization of 2DELs in silicon inversion layers in the 60s and 70s created unprecedented opportunities to probe subtle quantum effects, culminating in the discovery of the quantum Hall effect. In the following years, high quality 2DELs were obtained in doped quantum wells made in typical semiconductors like GaAs or CdTe. These systems became important test beds for quantum many-body effects due to Coulomb interaction, spin dynamics, spin-orbit coupling, effects of applied magnetic fields, as well as dissipation mechanisms. Here we focus on recent results involving chiral effects and intrinsic dissipation of collective spin modes: these are not only of fundamental interest but also important towards demonstrating new concepts in spintronics. Moreover, new realizations of 2DELs are emerging beyond traditional semiconductors, for instance in multilayer graphene, oxide interfaces, dichalcogenide monolayers, and many more. The concepts discussed in this review will be relevant also for these emerging systems.

show abstract

Intrinsic Damping of Collective Spin Modes in a Two-Dimensional Fermi Liquid with Spin-Orbit Coupling

Cited by 13 publications

References 37 publications

Chiral Spin Mode on the Surface of a Topological Insulator

Chiral Spin Mode on the Surface of a Topological Insulator

Electron density magnification of the collective spin-orbit field in quantum wells

Chirality and intrinsic dissipation of spin modes in two-dimensional electron liquids

Contact Info

Product

Resources

About