---
OA_place: repository
OA_type: green
_id: '389'
abstract:
- lang: eng
text: The coherent optical manipulation of solids is emerging as a promising way
to engineer novel quantum states of matter. 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
essential in realizing new photo-induced quantum phases. Similarly, dressing of
free-electron states near the surface of a solid generates Volkov states, which
are used to study nonlinear optics in atoms and semiconductors. The interaction
of these two dynamic states with each other remains an open experimental problem.
Here we use time- and angle-resolved photoemission spectroscopy (Tr-ARPES) to
selectively study the transition between these two states on the surface of the
topological insulator Bi2Se3. We find that the coupling between the two strongly
depends on the electron momentum, providing a route to enhance or inhibit it.
Moreover, by controlling the light polarization we can negate Volkov states to
generate pure Floquet-Bloch states. This work establishes a systematic path for
the coherent manipulation of solids via light-matter interaction.
acknowledgement: The authors would like to thank C. Lee for useful discussions. This
work is supported by US Department of Energy (DOE), Basic Energy Sciences, Division
of Materials Sciences and Engineering (experimental set-up, data acquisition and
theory), Army Research Office (electron spectrometer) and by the Gordon and Betty
Moore Foundation’s EPiQS Initiative through Grant GBMF4540 (data analysis).
article_processing_charge: No
article_type: letter_note
arxiv: 1
author:
- first_name: Fahad
full_name: Mahmood, Fahad
last_name: Mahmood
- first_name: Ching
full_name: Chan, Ching
last_name: Chan
- first_name: Zhanybek
full_name: Alpichshev, Zhanybek
id: 45E67A2A-F248-11E8-B48F-1D18A9856A87
last_name: Alpichshev
orcid: 0000-0002-7183-5203
- first_name: Dillon
full_name: Gardner, Dillon
last_name: Gardner
- first_name: Young
full_name: Lee, Young
last_name: Lee
- first_name: Patrick
full_name: Lee, Patrick
last_name: Lee
- first_name: Nuh
full_name: Gedik, Nuh
last_name: Gedik
citation:
ama: Mahmood F, Chan C, Alpichshev Z, et al. Selective scattering between Floquet
Bloch and Volkov states in a topological insulator. Nature Physics. 2016;12:306-310.
doi:10.1038/nphys3609
apa: Mahmood, F., Chan, C., Alpichshev, Z., Gardner, D., Lee, Y., Lee, P., &
Gedik, N. (2016). Selective scattering between Floquet Bloch and Volkov states
in a topological insulator. Nature Physics. Springer nature. https://doi.org/10.1038/nphys3609
chicago: Mahmood, Fahad, Ching Chan, Zhanybek Alpichshev, Dillon Gardner, Young
Lee, Patrick Lee, and Nuh Gedik. “Selective Scattering between Floquet Bloch and
Volkov States in a Topological Insulator.” Nature Physics. Springer nature,
2016. https://doi.org/10.1038/nphys3609.
ieee: F. Mahmood et al., “Selective scattering between Floquet Bloch and
Volkov states in a topological insulator,” Nature Physics, vol. 12. Springer
nature, pp. 306–310, 2016.
ista: Mahmood F, Chan C, Alpichshev Z, Gardner D, Lee Y, Lee P, Gedik N. 2016. Selective
scattering between Floquet Bloch and Volkov states in a topological insulator.
Nature Physics. 12, 306–310.
mla: Mahmood, Fahad, et al. “Selective Scattering between Floquet Bloch and Volkov
States in a Topological Insulator.” Nature Physics, vol. 12, Springer nature,
2016, pp. 306–10, doi:10.1038/nphys3609.
short: F. Mahmood, C. Chan, Z. Alpichshev, D. Gardner, Y. Lee, P. Lee, N. Gedik,
Nature Physics 12 (2016) 306–310.
date_created: 2018-12-11T11:46:11Z
date_published: 2016-04-01T00:00:00Z
date_updated: 2026-05-12T12:47:08Z
day: '01'
doi: 10.1038/nphys3609
extern: '1'
external_id:
arxiv:
- '1512.05714'
intvolume: ' 12'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1512.05714
month: '04'
oa: 1
oa_version: Preprint
page: 306 - 310
publication: Nature Physics
publication_identifier:
eissn:
- 1745-2481
issn:
- ' 1745-2473'
publication_status: published
publisher: Springer nature
publist_id: '7440'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Selective scattering between Floquet Bloch and Volkov states in a topological
insulator
type: journal_article
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
volume: 12
year: '2016'
...
---
_id: '18201'
abstract:
- lang: eng
text: Owing to thermal fluctuations, two-dimensional (2D) systems cannot undergo
a conventional phase transition associated with the breaking of a continuous symmetry1.
Nevertheless they may exhibit a phase transition to a state with quasi-long-range
order via the Berezinskii–Kosterlitz–Thouless (BKT) mechanism2. A paradigm example
is the 2D Bose fluid, such as a liquid helium film3, which cannot condense at
non-zero temperature although it becomes superfluid above a critical phase space
density. The quasi-long-range coherence and the microscopic nature of the BKT
transition were recently explored with ultracold atomic gases4,5,6. However, a
direct observation of superfluidity in terms of frictionless flow is still missing
for these systems. Here we probe the superfluidity of a 2D trapped Bose gas using
a moving obstacle formed by a micrometre-sized laser beam. We find a dramatic
variation of the response of the fluid, depending on its degree of degeneracy
at the obstacle location.
article_processing_charge: No
article_type: letter_note
arxiv: 1
author:
- first_name: Rémi
full_name: Desbuquois, Rémi
last_name: Desbuquois
- first_name: Lauriane
full_name: Chomaz, Lauriane
last_name: Chomaz
- first_name: Tarik
full_name: Yefsah, Tarik
last_name: Yefsah
- first_name: Julian
full_name: Leonard, Julian
id: b75b3f45-7995-11ef-9bfd-9a9cd02c3577
last_name: Leonard
- first_name: Jérôme
full_name: Beugnon, Jérôme
last_name: Beugnon
- first_name: Christof
full_name: Weitenberg, Christof
last_name: Weitenberg
- first_name: Jean
full_name: Dalibard, Jean
last_name: Dalibard
citation:
ama: Desbuquois R, Chomaz L, Yefsah T, et al. Superfluid behaviour of a two-dimensional
Bose gas. Nature Physics. 2012;8(9):645-648. doi:10.1038/nphys2378
apa: Desbuquois, R., Chomaz, L., Yefsah, T., Leonard, J., Beugnon, J., Weitenberg,
C., & Dalibard, J. (2012). Superfluid behaviour of a two-dimensional Bose
gas. Nature Physics. Springer Nature. https://doi.org/10.1038/nphys2378
chicago: Desbuquois, Rémi, Lauriane Chomaz, Tarik Yefsah, Julian Leonard, Jérôme
Beugnon, Christof Weitenberg, and Jean Dalibard. “Superfluid Behaviour of a Two-Dimensional
Bose Gas.” Nature Physics. Springer Nature, 2012. https://doi.org/10.1038/nphys2378.
ieee: R. Desbuquois et al., “Superfluid behaviour of a two-dimensional Bose
gas,” Nature Physics, vol. 8, no. 9. Springer Nature, pp. 645–648, 2012.
ista: Desbuquois R, Chomaz L, Yefsah T, Leonard J, Beugnon J, Weitenberg C, Dalibard
J. 2012. Superfluid behaviour of a two-dimensional Bose gas. Nature Physics. 8(9),
645–648.
mla: Desbuquois, Rémi, et al. “Superfluid Behaviour of a Two-Dimensional Bose Gas.”
Nature Physics, vol. 8, no. 9, Springer Nature, 2012, pp. 645–48, doi:10.1038/nphys2378.
short: R. Desbuquois, L. Chomaz, T. Yefsah, J. Leonard, J. Beugnon, C. Weitenberg,
J. Dalibard, Nature Physics 8 (2012) 645–648.
date_created: 2024-10-07T11:50:19Z
date_published: 2012-07-29T00:00:00Z
date_updated: 2024-10-07T12:05:22Z
day: '29'
doi: 10.1038/nphys2378
extern: '1'
external_id:
arxiv:
- '1205.4536'
intvolume: ' 8'
issue: '9'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1205.4536
month: '07'
oa: 1
oa_version: Preprint
page: 645-648
publication: Nature Physics
publication_identifier:
eissn:
- 1745-2481
issn:
- 1745-2473
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Superfluid behaviour of a two-dimensional Bose gas
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 8
year: '2012'
...