---
_id: '12213'
abstract:
- lang: eng
text: 'Motivated by properties-controlling potential of the strain, we investigate
strain dependence of structure, electronic, and magnetic properties of Sr2IrO4
using complementary theoretical tools: ab-initio calculations, analytical approaches
(rigid octahedra picture, Slater-Koster integrals), and extended t−J model. We
find that strain affects both Ir-Ir distance and Ir-O-Ir angle, and the rigid
octahedra picture is not relevant. Second, we find fundamentally different behavior
for compressive and tensile strain. One remarkable feature is the formation of
two subsets of bond- and orbital-dependent carriers, a compass-like model, under
compression. This originates from the strain-induced renormalization of the Ir-O-Ir
superexchange and O on-site energy. We also show that under compressive (tensile)
strain, Fermi surface becomes highly dispersive (relatively flat). Already at
a tensile strain of 1.5%, we observe spectral weight redistribution, with the
low-energy band acquiring almost purely singlet character. These results can be
directly compared with future experiments.'
acknowledgement: E.M.P. thanks Eugenio Paris, Thorsten Schmitt, Krzysztof Wohlfeld,
and other coauthors for an inspiring previous collaboration23, and is grateful to
Gang Cao, Ambrose Seo, and Jungho Kim for insightful discussions. R.R. acknowledges
helpful discussion with Sanjeev Kumar and Manuel Richter. This project has received
funding from the European Union’s Horizon 2020 research and innovation program under
the Marie Sklodowska-Curie grant agreement No 754411. C.C.C. acknowledges support
from the U.S. National Science Foundation Award No. DMR-2142801.
article_number: '90'
article_processing_charge: No
article_type: original
author:
- first_name: Ekaterina
full_name: Paerschke, Ekaterina
id: 8275014E-6063-11E9-9B7F-6338E6697425
last_name: Paerschke
orcid: 0000-0003-0853-8182
- first_name: Wei-Chih
full_name: Chen, Wei-Chih
last_name: Chen
- first_name: Rajyavardhan
full_name: Ray, Rajyavardhan
last_name: Ray
- first_name: Cheng-Chien
full_name: Chen, Cheng-Chien
last_name: Chen
citation:
ama: Paerschke E, Chen W-C, Ray R, Chen C-C. Evolution of electronic and magnetic
properties of Sr₂IrO₄ under strain. npj Quantum Materials. 2022;7. doi:10.1038/s41535-022-00496-w
apa: Paerschke, E., Chen, W.-C., Ray, R., & Chen, C.-C. (2022). Evolution of
electronic and magnetic properties of Sr₂IrO₄ under strain. Npj Quantum Materials.
Springer Nature. https://doi.org/10.1038/s41535-022-00496-w
chicago: Paerschke, Ekaterina, Wei-Chih Chen, Rajyavardhan Ray, and Cheng-Chien
Chen. “Evolution of Electronic and Magnetic Properties of Sr₂IrO₄ under Strain.”
Npj Quantum Materials. Springer Nature, 2022. https://doi.org/10.1038/s41535-022-00496-w.
ieee: E. Paerschke, W.-C. Chen, R. Ray, and C.-C. Chen, “Evolution of electronic
and magnetic properties of Sr₂IrO₄ under strain,” npj Quantum Materials,
vol. 7. Springer Nature, 2022.
ista: Paerschke E, Chen W-C, Ray R, Chen C-C. 2022. Evolution of electronic and
magnetic properties of Sr₂IrO₄ under strain. npj Quantum Materials. 7, 90.
mla: Paerschke, Ekaterina, et al. “Evolution of Electronic and Magnetic Properties
of Sr₂IrO₄ under Strain.” Npj Quantum Materials, vol. 7, 90, Springer Nature,
2022, doi:10.1038/s41535-022-00496-w.
short: E. Paerschke, W.-C. Chen, R. Ray, C.-C. Chen, Npj Quantum Materials 7 (2022).
date_created: 2023-01-16T09:46:01Z
date_published: 2022-09-10T00:00:00Z
date_updated: 2023-08-04T09:23:43Z
day: '10'
ddc:
- '530'
department:
- _id: MiLe
doi: 10.1038/s41535-022-00496-w
ec_funded: 1
external_id:
isi:
- '000852381200003'
file:
- access_level: open_access
checksum: d93b477b5b95c0d1b8f9fef90a81f565
content_type: application/pdf
creator: dernst
date_created: 2023-01-27T07:59:27Z
date_updated: 2023-01-27T07:59:27Z
file_id: '12414'
file_name: 2022_NPJ_Paerschke.pdf
file_size: 1852598
relation: main_file
success: 1
file_date_updated: 2023-01-27T07:59:27Z
has_accepted_license: '1'
intvolume: ' 7'
isi: 1
keyword:
- Condensed Matter Physics
- Electronic
- Optical and Magnetic Materials
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '09'
oa: 1
oa_version: Published Version
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '754411'
name: ISTplus - Postdoctoral Fellowships
publication: npj Quantum Materials
publication_identifier:
eissn:
- 2397-4648
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
link:
- relation: erratum
url: https://doi.org/10.1038/s41535-022-00510-1
scopus_import: '1'
status: public
title: Evolution of electronic and magnetic properties of Sr₂IrO₄ under strain
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 7
year: '2022'
...
---
_id: '12154'
abstract:
- lang: eng
text: We review our theoretical results of the sound propagation in two-dimensional
(2D) systems of ultracold fermionic and bosonic atoms. In the superfluid phase,
characterized by the spontaneous symmetry breaking of the U(1) symmetry, there
is the coexistence of first and second sound. In the case of weakly-interacting
repulsive bosons, we model the recent measurements of the sound velocities of
39K atoms in 2D obtained in the weakly-interacting regime and around the Berezinskii–Kosterlitz–Thouless
(BKT) superfluid-to-normal transition temperature. In particular, we perform a
quite accurate computation of the superfluid density and show that it is reasonably
consistent with the experimental results. For superfluid attractive fermions,
we calculate the first and second sound velocities across the whole BCS-BEC crossover.
In the low-temperature regime, we reproduce the recent measurements of first-sound
speed with 6Li atoms. We also predict that there is mixing between sound modes
only in the finite-temperature BEC regime.
acknowledgement: "This research is partially supported by University of Padova, BIRD
grant “Ultracold atoms\r\nin curved geometries”. KF is supported by Fondazione CARIPARO
with a PhD fellowship. AT is\r\npartially supported by French National Research
Agency ANR Grant Droplets N. ANR-19-CE30-0003-02. LS thanks Herwig Ott and Sandro
Wimberger for their kind invitation to the\r\nInternational Workshop “Quantum Transport
with ultracold atoms” (2022)."
article_number: '2182'
article_processing_charge: Yes
article_type: original
author:
- first_name: Luca
full_name: Salasnich, Luca
last_name: Salasnich
- first_name: Alberto
full_name: Cappellaro, Alberto
id: 9d13b3cb-30a2-11eb-80dc-f772505e8660
last_name: Cappellaro
orcid: 0000-0001-6110-2359
- first_name: Koichiro
full_name: Furutani, Koichiro
last_name: Furutani
- first_name: Andrea
full_name: Tononi, Andrea
last_name: Tononi
- first_name: Giacomo
full_name: Bighin, Giacomo
id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87
last_name: Bighin
orcid: 0000-0001-8823-9777
citation:
ama: Salasnich L, Cappellaro A, Furutani K, Tononi A, Bighin G. First and second
sound in two-dimensional bosonic and fermionic superfluids. Symmetry. 2022;14(10).
doi:10.3390/sym14102182
apa: Salasnich, L., Cappellaro, A., Furutani, K., Tononi, A., & Bighin, G. (2022).
First and second sound in two-dimensional bosonic and fermionic superfluids. Symmetry.
MDPI. https://doi.org/10.3390/sym14102182
chicago: Salasnich, Luca, Alberto Cappellaro, Koichiro Furutani, Andrea Tononi,
and Giacomo Bighin. “First and Second Sound in Two-Dimensional Bosonic and Fermionic
Superfluids.” Symmetry. MDPI, 2022. https://doi.org/10.3390/sym14102182.
ieee: L. Salasnich, A. Cappellaro, K. Furutani, A. Tononi, and G. Bighin, “First
and second sound in two-dimensional bosonic and fermionic superfluids,” Symmetry,
vol. 14, no. 10. MDPI, 2022.
ista: Salasnich L, Cappellaro A, Furutani K, Tononi A, Bighin G. 2022. First and
second sound in two-dimensional bosonic and fermionic superfluids. Symmetry. 14(10),
2182.
mla: Salasnich, Luca, et al. “First and Second Sound in Two-Dimensional Bosonic
and Fermionic Superfluids.” Symmetry, vol. 14, no. 10, 2182, MDPI, 2022,
doi:10.3390/sym14102182.
short: L. Salasnich, A. Cappellaro, K. Furutani, A. Tononi, G. Bighin, Symmetry
14 (2022).
date_created: 2023-01-12T12:08:31Z
date_published: 2022-10-17T00:00:00Z
date_updated: 2023-08-09T10:13:17Z
day: '17'
ddc:
- '530'
department:
- _id: MiLe
doi: 10.3390/sym14102182
external_id:
isi:
- '000875039200001'
file:
- access_level: open_access
checksum: 9b6bd0e484834dd76d7b26e3c5fba8bd
content_type: application/pdf
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date_created: 2023-01-24T10:56:12Z
date_updated: 2023-01-24T10:56:12Z
file_id: '12361'
file_name: 2022_Symmetry_Salsnich.pdf
file_size: 843723
relation: main_file
success: 1
file_date_updated: 2023-01-24T10:56:12Z
has_accepted_license: '1'
intvolume: ' 14'
isi: 1
issue: '10'
keyword:
- Physics and Astronomy (miscellaneous)
- General Mathematics
- Chemistry (miscellaneous)
- Computer Science (miscellaneous)
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
publication: Symmetry
publication_identifier:
issn:
- 2073-8994
publication_status: published
publisher: MDPI
quality_controlled: '1'
scopus_import: '1'
status: public
title: First and second sound in two-dimensional bosonic and fermionic superfluids
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 14
year: '2022'
...
---
_id: '10759'
abstract:
- lang: eng
text: In this Thesis, I study composite quantum impurities with variational techniques,
both inspired by machine learning as well as fully analytic. I supplement this
with exploration of other applications of machine learning, in particular artificial
neural networks, in many-body physics. In Chapters 3 and 4, I study quasiparticle
systems with variational approach. I derive a Hamiltonian describing the angulon
quasiparticle in the presence of a magnetic field. I apply analytic variational
treatment to this Hamiltonian. Then, I introduce a variational approach for non-additive
systems, based on artificial neural networks. I exemplify this approach on the
example of the polaron quasiparticle (Fröhlich Hamiltonian). In Chapter 5, I continue
using artificial neural networks, albeit in a different setting. I apply artificial
neural networks to detect phases from snapshots of two types physical systems.
Namely, I study Monte Carlo snapshots of multilayer classical spin models as well
as molecular dynamics maps of colloidal systems. The main type of networks that
I use here are convolutional neural networks, known for their applicability to
image data.
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Wojciech
full_name: Rzadkowski, Wojciech
id: 48C55298-F248-11E8-B48F-1D18A9856A87
last_name: Rzadkowski
orcid: 0000-0002-1106-4419
citation:
ama: Rzadkowski W. Analytic and machine learning approaches to composite quantum
impurities. 2022. doi:10.15479/at:ista:10759
apa: Rzadkowski, W. (2022). Analytic and machine learning approaches to composite
quantum impurities. Institute of Science and Technology Austria. https://doi.org/10.15479/at:ista:10759
chicago: Rzadkowski, Wojciech. “Analytic and Machine Learning Approaches to Composite
Quantum Impurities.” Institute of Science and Technology Austria, 2022. https://doi.org/10.15479/at:ista:10759.
ieee: W. Rzadkowski, “Analytic and machine learning approaches to composite quantum
impurities,” Institute of Science and Technology Austria, 2022.
ista: Rzadkowski W. 2022. Analytic and machine learning approaches to composite
quantum impurities. Institute of Science and Technology Austria.
mla: Rzadkowski, Wojciech. Analytic and Machine Learning Approaches to Composite
Quantum Impurities. Institute of Science and Technology Austria, 2022, doi:10.15479/at:ista:10759.
short: W. Rzadkowski, Analytic and Machine Learning Approaches to Composite Quantum
Impurities, Institute of Science and Technology Austria, 2022.
date_created: 2022-02-16T13:27:37Z
date_published: 2022-02-21T00:00:00Z
date_updated: 2024-02-28T13:01:59Z
day: '21'
ddc:
- '530'
degree_awarded: PhD
department:
- _id: GradSch
- _id: MiLe
doi: 10.15479/at:ista:10759
ec_funded: 1
file:
- access_level: closed
checksum: 0fc54ad1eaede879c665ac9b53c93e22
content_type: application/zip
creator: wrzadkow
date_created: 2022-02-21T13:58:16Z
date_updated: 2022-02-22T07:20:12Z
file_id: '10785'
file_name: Rzadkowski_thesis_final_source.zip
file_size: 17668233
relation: source_file
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checksum: 22d2d7af37ca31f6b1730c26cac7bced
content_type: application/pdf
creator: wrzadkow
date_created: 2022-02-21T14:02:54Z
date_updated: 2022-02-21T14:02:54Z
file_id: '10786'
file_name: Rzadkowski_thesis_final.pdf
file_size: 13307331
relation: main_file
success: 1
file_date_updated: 2022-02-22T07:20:12Z
has_accepted_license: '1'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
page: '120'
project:
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '665385'
name: International IST Doctoral Program
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
record:
- id: '10762'
relation: part_of_dissertation
status: public
- id: '8644'
relation: part_of_dissertation
status: public
- id: '7956'
relation: part_of_dissertation
status: public
- id: '415'
relation: part_of_dissertation
status: public
status: public
supervisor:
- first_name: Mikhail
full_name: Lemeshko, Mikhail
id: 37CB05FA-F248-11E8-B48F-1D18A9856A87
last_name: Lemeshko
orcid: 0000-0002-6990-7802
title: Analytic and machine learning approaches to composite quantum impurities
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2022'
...
---
_id: '10585'
abstract:
- lang: eng
text: Recently it was shown that anyons on the two-sphere naturally arise from a
system of molecular impurities exchanging angular momentum with a many-particle
bath (Phys. Rev. Lett. 126, 015301 (2021)). Here we further advance this approach
and rigorously demonstrate that in the experimentally realized regime the lowest
spectrum of two linear molecules immersed in superfluid helium corresponds to
the spectrum of two anyons on the sphere. We develop the formalism within the
framework of the recently experimentally observed angulon quasiparticle
acknowledgement: D. Lundholm acknowledges financial support from the Göran Gustafsson
Foundation (grant no. 1804).
article_number: '106'
article_processing_charge: Yes
article_type: original
author:
- first_name: Morris
full_name: Brooks, Morris
id: B7ECF9FC-AA38-11E9-AC9A-0930E6697425
last_name: Brooks
orcid: 0000-0002-6249-0928
- first_name: Mikhail
full_name: Lemeshko, Mikhail
id: 37CB05FA-F248-11E8-B48F-1D18A9856A87
last_name: Lemeshko
orcid: 0000-0002-6990-7802
- first_name: Douglas
full_name: Lundholm, Douglas
last_name: Lundholm
- first_name: Enderalp
full_name: Yakaboylu, Enderalp
id: 38CB71F6-F248-11E8-B48F-1D18A9856A87
last_name: Yakaboylu
orcid: 0000-0001-5973-0874
citation:
ama: Brooks M, Lemeshko M, Lundholm D, Yakaboylu E. Emergence of anyons on the two-sphere
in molecular impurities. Atoms. 2021;9(4). doi:10.3390/atoms9040106
apa: Brooks, M., Lemeshko, M., Lundholm, D., & Yakaboylu, E. (2021). Emergence
of anyons on the two-sphere in molecular impurities. Atoms. MDPI. https://doi.org/10.3390/atoms9040106
chicago: Brooks, Morris, Mikhail Lemeshko, Douglas Lundholm, and Enderalp Yakaboylu.
“Emergence of Anyons on the Two-Sphere in Molecular Impurities.” Atoms.
MDPI, 2021. https://doi.org/10.3390/atoms9040106.
ieee: M. Brooks, M. Lemeshko, D. Lundholm, and E. Yakaboylu, “Emergence of anyons
on the two-sphere in molecular impurities,” Atoms, vol. 9, no. 4. MDPI,
2021.
ista: Brooks M, Lemeshko M, Lundholm D, Yakaboylu E. 2021. Emergence of anyons on
the two-sphere in molecular impurities. Atoms. 9(4), 106.
mla: Brooks, Morris, et al. “Emergence of Anyons on the Two-Sphere in Molecular
Impurities.” Atoms, vol. 9, no. 4, 106, MDPI, 2021, doi:10.3390/atoms9040106.
short: M. Brooks, M. Lemeshko, D. Lundholm, E. Yakaboylu, Atoms 9 (2021).
date_created: 2022-01-02T23:01:33Z
date_published: 2021-12-02T00:00:00Z
date_updated: 2023-06-15T14:51:49Z
day: '02'
ddc:
- '530'
department:
- _id: MiLe
- _id: RoSe
doi: 10.3390/atoms9040106
external_id:
arxiv:
- '2108.06966'
file:
- access_level: open_access
checksum: d0e44b95f36c9e06724f66832af0f8c3
content_type: application/pdf
creator: alisjak
date_created: 2022-01-03T10:15:05Z
date_updated: 2022-01-03T10:15:05Z
file_id: '10592'
file_name: 2021_Atoms_Brooks.pdf
file_size: 303070
relation: main_file
success: 1
file_date_updated: 2022-01-03T10:15:05Z
has_accepted_license: '1'
intvolume: ' 9'
issue: '4'
keyword:
- anyons
- quasiparticles
- Quantum Hall Effect
- topological states of matter
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
publication: Atoms
publication_identifier:
eissn:
- 2218-2004
publication_status: published
publisher: MDPI
quality_controlled: '1'
scopus_import: '1'
status: public
title: Emergence of anyons on the two-sphere in molecular impurities
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 9
year: '2021'
...
---
_id: '8816'
abstract:
- lang: eng
text: Area-dependent quantum field theory is a modification of two-dimensional topological
quantum field theory, where one equips each connected component of a bordism with
a positive real number—interpreted as area—which behaves additively under glueing.
As opposed to topological theories, in area-dependent theories the state spaces
can be infinite-dimensional. We introduce the notion of regularised Frobenius
algebras in Hilbert spaces and show that area-dependent theories are in one-to-one
correspondence to commutative regularised Frobenius algebras. We also provide
a state sum construction for area-dependent theories. Our main example is two-dimensional
Yang–Mills theory with compact gauge group, which we treat in detail.
acknowledgement: The authors thank Yuki Arano, Nils Carqueville, Alexei Davydov, Reiner
Lauterbach, Pau Enrique Moliner, Chris Heunen, André Henriques, Ehud Meir, Catherine
Meusburger, Gregor Schaumann, Richard Szabo and Stefan Wagner for helpful discussions
and comments. We also thank the referees for their detailed comments which significantly
improved the exposition of this paper. LS is supported by the DFG Research Training
Group 1670 “Mathematics Inspired by String Theory and Quantum Field Theory”. Open
access funding provided by Institute of Science and Technology (IST Austria).
article_processing_charge: Yes (via OA deal)
article_type: original
author:
- first_name: Ingo
full_name: Runkel, Ingo
last_name: Runkel
- first_name: Lorant
full_name: Szegedy, Lorant
id: 7943226E-220E-11EA-94C7-D59F3DDC885E
last_name: Szegedy
orcid: 0000-0003-2834-5054
citation:
ama: Runkel I, Szegedy L. Area-dependent quantum field theory. Communications
in Mathematical Physics. 2021;381(1):83–117. doi:10.1007/s00220-020-03902-1
apa: Runkel, I., & Szegedy, L. (2021). Area-dependent quantum field theory.
Communications in Mathematical Physics. Springer Nature. https://doi.org/10.1007/s00220-020-03902-1
chicago: Runkel, Ingo, and Lorant Szegedy. “Area-Dependent Quantum Field Theory.”
Communications in Mathematical Physics. Springer Nature, 2021. https://doi.org/10.1007/s00220-020-03902-1.
ieee: I. Runkel and L. Szegedy, “Area-dependent quantum field theory,” Communications
in Mathematical Physics, vol. 381, no. 1. Springer Nature, pp. 83–117, 2021.
ista: Runkel I, Szegedy L. 2021. Area-dependent quantum field theory. Communications
in Mathematical Physics. 381(1), 83–117.
mla: Runkel, Ingo, and Lorant Szegedy. “Area-Dependent Quantum Field Theory.” Communications
in Mathematical Physics, vol. 381, no. 1, Springer Nature, 2021, pp. 83–117,
doi:10.1007/s00220-020-03902-1.
short: I. Runkel, L. Szegedy, Communications in Mathematical Physics 381 (2021)
83–117.
date_created: 2020-11-29T23:01:17Z
date_published: 2021-01-01T00:00:00Z
date_updated: 2023-08-04T11:13:35Z
day: '01'
ddc:
- '510'
department:
- _id: MiLe
doi: 10.1007/s00220-020-03902-1
external_id:
isi:
- '000591139000001'
file:
- access_level: open_access
checksum: 6f451f9c2b74bedbc30cf884a3e02670
content_type: application/pdf
creator: dernst
date_created: 2021-02-03T15:00:30Z
date_updated: 2021-02-03T15:00:30Z
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file_name: 2021_CommMathPhys_Runkel.pdf
file_size: 790526
relation: main_file
success: 1
file_date_updated: 2021-02-03T15:00:30Z
has_accepted_license: '1'
intvolume: ' 381'
isi: 1
issue: '1'
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
page: 83–117
project:
- _id: B67AFEDC-15C9-11EA-A837-991A96BB2854
name: IST Austria Open Access Fund
publication: Communications in Mathematical Physics
publication_identifier:
eissn:
- '14320916'
issn:
- '00103616'
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Area-dependent quantum field theory
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 381
year: '2021'
...