# Selective scattering between Floquet–Bloch and Volkov states in a topological insulator

@article{Mahmood2015SelectiveSB, title={Selective scattering between Floquet–Bloch and Volkov states in a topological insulator}, author={Fahad Mahmood and Ching-Kit Chan and Zhanybek Alpichshev and Dillon R. Gardner and Young S. Lee and Patrick A. Lee and Nuh Gedik}, journal={Nature Physics}, year={2015}, volume={12}, pages={306-310} }

Time- and angle-resolved photoelectron spectroscopy experiments are used to monitor the transition between Floquet–Bloch and Volkov states in the topological insulator Bi2Se3. The coherent optical manipulation of solids is emerging as a promising way to engineer novel quantum states of matter1,2,3,4,5. The strong time-periodic potential of intense laser light can be used to generate hybrid photon–electron states. Interaction of light with Bloch states leads to Floquet–Bloch states, which are…

## 182 Citations

### Steady Floquet–Andreev states in graphene Josephson junctions

- PhysicsNature
- 2022

Engineering quantum states through light–matter interaction has created a paradigm in condensed-matter physics. A representative example is the Floquet–Bloch state, which is generated by…

### Steady Floquet-Andreev States Probed by Tunnelling Spectroscopy

- Physics
- 2021

Engineering quantum states through light-matter interaction has created a new paradigm in condensed matter physics. A representative example is the Floquet-Bloch state, which is generated by…

### Probing topological Floquet states in WSe2 using circular dichroism in time- and angle-resolved photoemission spectroscopy

- PhysicsCommunications Physics
- 2022

Observing signatures of light-induced topological Floquet states in materials has been shown to be very challenging. Angle-resolved photoemission spectroscopy (ARPES) is well suited for the…

### How Circular Dichroism in Time- and Angle-Resolved Photoemission Can Be Used to Spectroscopically Detect Transient Topological States in Graphene

- PhysicsPhysical Review X
- 2020

Pumping graphene with circularly polarized light is the archetype of light-tailoring topological bands. Realizing the induced Floquet-Chern insulator state and tracing clear experimental manifestions…

### Dynamical symmetry of strongly light-driven electronic system in crystalline solids

- PhysicsCommunications Physics
- 2020

The Floquet state, which is a periodically and intensely light-driven quantum state in solids, has been attracting attention as a novel state that is coherently controllable on an ultrafast time…

### Floquet topological insulators: from band structure engineering to novel non-equilibrium quantum phenomena.

- Physics
- 2019

We review methods for using time-periodic fields (e.g., laser or microwave fields) to induce non-equilibrium topological phenomena in quantum many-body systems. We discuss how such fields can be used…

### Survival of Floquet–Bloch States in the Presence of Scattering

- PhysicsNano letters
- 2021

It is found that Floquet–Bloch states will be destroyed if scattering—activated by electronic excitations—prevents the Bloch electrons from following the driving field coherently, indicating the importance of long scattering times combined with strong driving fields for the successful realization of various Floquet phenomena.

### Photoinduced Nonequilibrium Topological States in Strained Black Phosphorus.

- PhysicsPhysical review letters
- 2018

Black phosphorus exhibits a photon-dressed Floquet-Dirac semimetal state, which can be continuously tuned by changing the direction, intensity, and frequency of the incident laser, and topological surface states exhibit nonequilibrium electron transport in a direction locked by the helicity of CPL.

### Observation of a giant mass enhancement in the ultrafast electron dynamics of a topological semimetal

- PhysicsCommunications Physics
- 2021

Topological phases of matter offer exciting possibilities to realize lossless charge and spin information transport on ultrafast time scales. However, this requires detailed knowledge of their…

### Exciton-coherence generation through diabatic and adiabatic dynamics of Floquet state

- Physics
- 2022

Floquet engineering of electronic systems is a promising way of controlling quantum material properties on an ultrafast time scale. So far, the energy structure of Floquet states in solids has been…

## References

SHOWING 1-10 OF 32 REFERENCES

### Observation of Floquet-Bloch States on the Surface of a Topological Insulator

- PhysicsScience
- 2013

Using time- and angle-resolved photoemission spectroscopy, it is shown that an intense ultrashort midinfrared pulse with energy below the bulk band gap hybridizes with the surface Dirac fermions of a topological insulator to form Floquet-Bloch bands.

### Ultrafast surface carrier dynamics in the topological insulator Bi₂Te₃.

- PhysicsNano letters
- 2012

It is found that the thermalization of the surface states is initially determined by interband scattering from the bulk conduction band, lasting for about 0.5 ps; this establishes a correlation between the nanoscale thickness of the bulk charge reservoir and the evolution of the ultrafast carrier dynamics in the surface Dirac cone.

### Floquet topological insulator in semiconductor quantum wells

- Physics
- 2011

Topological phases of matter have captured our imagination over the past few years, with tantalizing properties such as robust edge modes and exotic non-Abelian excitations, and potential…

### Controlled Population of Floquet-Bloch States via Coupling to Bose and Fermi Baths

- Physics
- 2015

External driving is emerging as a promising tool for exploring new phases in quantum systems. The intrinsically non-equilibrium states that result, however, are challenging to describe and control.…

### Measurement of intrinsic dirac fermion cooling on the surface of the topological insulator Bi2Se3 using time-resolved and angle-resolved photoemission spectroscopy.

- PhysicsPhysical review letters
- 2012

Analysis of the evolution of surface states and bulk band spectra in a prototypical topological insulator reveals strong phonon-assisted surface-bulk coupling at high lattice temperature and total suppression of inelastic scattering between the surface and the bulk at low latticeTemperature.

### Optical response of graphene under intense terahertz fields

- Physics
- 2011

Optical responses of graphene in the presence of intense circularly and linearly polarized terahertz fields are investigated based on the Floquet theory. We examine the energy spectrum and density of…

### Driven electronic states at the surface of a topological insulator

- Physics
- 2013

(Received 29 May 2013; revised manuscript received 11 August 2013; published 23 October 2013) Motivated by recent photoemission experiments on the surface of topological insulators we compute the…

### Ultrafast optical excitation of a persistent surface-state population in the topological insulator Bi2Se3.

- PhysicsPhysical review letters
- 2012

Using femtosecond time- and angle-resolved photoemission spectroscopy, the nonequilibrium dynamics of the topological insulator Bi2Se3 is investigated, finding an unusually long-lived population of a metallic Dirac surface state with spin texture that may present a channel in which to drive transient spin-polarized currents.

### Tuning a Schottky barrier in a photoexcited topological insulator with transient Dirac cone electron-hole asymmetry.

- PhysicsNature communications
- 2014

The interplay of surface and bulk transient carrier dynamics in a photoexcited topological insulator can control an essential parameter for photoconductivity-the balance between excess electrons and holes in the Dirac cone.

### Observation of a warped helical spin texture in Bi2Se3 from circular dichroism angle-resolved photoemission spectroscopy.

- PhysicsPhysical review letters
- 2011

Direct evidence of circular dichroism from the surface states of Bi(2)Se(3) is reported using laser-based time-of-flight angle-resolved photoemission spectroscopy and the technique may be a powerful probe of the spin texture of spin-orbit coupled materials in general.