---
_id: '988'
abstract:
- lang: eng
text: The current-phase relation (CPR) of a Josephson junction (JJ) determines how
the supercurrent evolves with the superconducting phase difference across the
junction. Knowledge of the CPR is essential in order to understand the response
of a JJ to various external parameters. Despite the rising interest in ultraclean
encapsulated graphene JJs, the CPR of such junctions remains unknown. Here, we
use a fully gate-tunable graphene superconducting quantum intereference device
(SQUID) to determine the CPR of ballistic graphene JJs. Each of the two JJs in
the SQUID is made with graphene encapsulated in hexagonal boron nitride. By independently
controlling the critical current of the JJs, we can operate the SQUID either in
a symmetric or asymmetric configuration. The highly asymmetric SQUID allows us
to phase-bias one of the JJs and thereby directly obtain its CPR. The CPR is found
to be skewed, deviating significantly from a sinusoidal form. The skewness can
be tuned with the gate voltage and oscillates in antiphase with Fabry-Pérot resistance
oscillations of the ballistic graphene cavity. We compare our experiments with
tight-binding calculations that include realistic graphene-superconductor interfaces
and find a good qualitative agreement.
article_processing_charge: No
author:
- first_name: Gaurav
full_name: Nanda, Gaurav
last_name: Nanda
- first_name: Juan L
full_name: Aguilera Servin, Juan L
id: 2A67C376-F248-11E8-B48F-1D18A9856A87
last_name: Aguilera Servin
orcid: 0000-0002-2862-8372
- first_name: Péter
full_name: Rakyta, Péter
last_name: Rakyta
- first_name: Andor
full_name: Kormányos, Andor
last_name: Kormányos
- first_name: Reinhold
full_name: Kleiner, Reinhold
last_name: Kleiner
- first_name: Dieter
full_name: Koelle, Dieter
last_name: Koelle
- first_name: Kazuo
full_name: Watanabe, Kazuo
last_name: Watanabe
- first_name: Takashi
full_name: Taniguchi, Takashi
last_name: Taniguchi
- first_name: Lieven
full_name: Vandersypen, Lieven
last_name: Vandersypen
- first_name: Srijit
full_name: Goswami, Srijit
last_name: Goswami
citation:
ama: Nanda G, Aguilera Servin JL, Rakyta P, et al. Current-phase relation of ballistic
graphene Josephson junctions. Nano Letters. 2017;17(6):3396-3401. doi:10.1021/acs.nanolett.7b00097
apa: Nanda, G., Aguilera Servin, J. L., Rakyta, P., Kormányos, A., Kleiner, R.,
Koelle, D., … Goswami, S. (2017). Current-phase relation of ballistic graphene
Josephson junctions. Nano Letters. American Chemical Society. https://doi.org/10.1021/acs.nanolett.7b00097
chicago: Nanda, Gaurav, Juan L Aguilera Servin, Péter Rakyta, Andor Kormányos, Reinhold
Kleiner, Dieter Koelle, Kazuo Watanabe, Takashi Taniguchi, Lieven Vandersypen,
and Srijit Goswami. “Current-Phase Relation of Ballistic Graphene Josephson Junctions.”
Nano Letters. American Chemical Society, 2017. https://doi.org/10.1021/acs.nanolett.7b00097.
ieee: G. Nanda et al., “Current-phase relation of ballistic graphene Josephson
junctions,” Nano Letters, vol. 17, no. 6. American Chemical Society, pp.
3396–3401, 2017.
ista: Nanda G, Aguilera Servin JL, Rakyta P, Kormányos A, Kleiner R, Koelle D, Watanabe
K, Taniguchi T, Vandersypen L, Goswami S. 2017. Current-phase relation of ballistic
graphene Josephson junctions. Nano Letters. 17(6), 3396–3401.
mla: Nanda, Gaurav, et al. “Current-Phase Relation of Ballistic Graphene Josephson
Junctions.” Nano Letters, vol. 17, no. 6, American Chemical Society, 2017,
pp. 3396–401, doi:10.1021/acs.nanolett.7b00097.
short: G. Nanda, J.L. Aguilera Servin, P. Rakyta, A. Kormányos, R. Kleiner, D. Koelle,
K. Watanabe, T. Taniguchi, L. Vandersypen, S. Goswami, Nano Letters 17 (2017)
3396–3401.
date_created: 2018-12-11T11:49:33Z
date_published: 2017-05-05T00:00:00Z
date_updated: 2025-07-10T12:02:04Z
day: '05'
ddc:
- '621'
department:
- _id: NanoFab
doi: 10.1021/acs.nanolett.7b00097
external_id:
isi:
- '000403631600011'
file:
- access_level: open_access
checksum: 22021daa90cf13b01becd776838acb7b
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:13:50Z
date_updated: 2020-07-14T12:48:18Z
file_id: '5037'
file_name: IST-2017-826-v1+1_2017_Aguilera-Servin_Current.pdf
file_size: 508638
relation: main_file
file_date_updated: 2020-07-14T12:48:18Z
has_accepted_license: '1'
intvolume: ' 17'
isi: 1
issue: '6'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: 3396 - 3401
publication: Nano Letters
publication_identifier:
issn:
- 1530-6984
publication_status: published
publisher: American Chemical Society
publist_id: '6412'
pubrep_id: '826'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Current-phase relation of ballistic graphene Josephson junctions
tmp:
image: /images/cc_by_nc_nd.png
legal_code_url: https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode
name: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
(CC BY-NC-ND 4.0)
short: CC BY-NC-ND (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 17
year: '2017'
...
---
_id: '1154'
abstract:
- lang: eng
text: "Cellular locomotion is a central hallmark of eukaryotic life. It is governed
by cell-extrinsic molecular factors, which can either emerge in the soluble phase
or as immobilized, often adhesive ligands. To encode for direction, every cue
must be present as a spatial or temporal gradient. Here, we developed a microfluidic
chamber that allows measurement of cell migration in combined response to surface
immobilized and soluble molecular gradients. As a proof of principle we study
the response of dendritic cells to their major guidance cues, chemokines. The
majority of data on chemokine gradient sensing is based on in vitro studies employing
soluble gradients. Despite evidence suggesting that in vivo chemokines are often
immobilized to sugar residues, limited information is available how cells respond
to immobilized chemokines. We tracked migration of dendritic cells towards immobilized
gradients of the chemokine CCL21 and varying superimposed soluble gradients of
CCL19. Differential migratory patterns illustrate the potential of our setup to
quantitatively study the competitive response to both types of gradients. Beyond
chemokines our approach is broadly applicable to alternative systems of chemo-
and haptotaxis such as cells migrating along gradients of adhesion receptor ligands
vs. any soluble cue. \r\n"
acknowledgement: 'This work was supported by the Swiss National Science Foundation
(Ambizione fellowship; PZ00P3-154733 to M.M.), the Swiss Multiple Sclerosis Society
(research support to M.M.), a fellowship from the Boehringer Ingelheim Fonds (BIF)
to J.S., the European Research Council (grant ERC GA 281556) and a START award from
the Austrian Science Foundation (FWF) to M.S. #BioimagingFacility'
article_number: '36440'
article_processing_charge: No
author:
- first_name: Jan
full_name: Schwarz, Jan
id: 346C1EC6-F248-11E8-B48F-1D18A9856A87
last_name: Schwarz
- first_name: Veronika
full_name: Bierbaum, Veronika
id: 3FD04378-F248-11E8-B48F-1D18A9856A87
last_name: Bierbaum
- first_name: Jack
full_name: Merrin, Jack
id: 4515C308-F248-11E8-B48F-1D18A9856A87
last_name: Merrin
orcid: 0000-0001-5145-4609
- first_name: Tino
full_name: Frank, Tino
last_name: Frank
- first_name: Robert
full_name: Hauschild, Robert
id: 4E01D6B4-F248-11E8-B48F-1D18A9856A87
last_name: Hauschild
orcid: 0000-0001-9843-3522
- first_name: Mark Tobias
full_name: Bollenbach, Mark Tobias
id: 3E6DB97A-F248-11E8-B48F-1D18A9856A87
last_name: Bollenbach
orcid: 0000-0003-4398-476X
- first_name: Savaş
full_name: Tay, Savaş
last_name: Tay
- first_name: Michael K
full_name: Sixt, Michael K
id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
last_name: Sixt
orcid: 0000-0002-6620-9179
- first_name: Matthias
full_name: Mehling, Matthias
id: 3C23B994-F248-11E8-B48F-1D18A9856A87
last_name: Mehling
orcid: 0000-0001-8599-1226
citation:
ama: Schwarz J, Bierbaum V, Merrin J, et al. A microfluidic device for measuring
cell migration towards substrate bound and soluble chemokine gradients. Scientific
Reports. 2016;6. doi:10.1038/srep36440
apa: Schwarz, J., Bierbaum, V., Merrin, J., Frank, T., Hauschild, R., Bollenbach,
M. T., … Mehling, M. (2016). A microfluidic device for measuring cell migration
towards substrate bound and soluble chemokine gradients. Scientific Reports.
Nature Publishing Group. https://doi.org/10.1038/srep36440
chicago: Schwarz, Jan, Veronika Bierbaum, Jack Merrin, Tino Frank, Robert Hauschild,
Mark Tobias Bollenbach, Savaş Tay, Michael K Sixt, and Matthias Mehling. “A Microfluidic
Device for Measuring Cell Migration towards Substrate Bound and Soluble Chemokine
Gradients.” Scientific Reports. Nature Publishing Group, 2016. https://doi.org/10.1038/srep36440.
ieee: J. Schwarz et al., “A microfluidic device for measuring cell migration
towards substrate bound and soluble chemokine gradients,” Scientific Reports,
vol. 6. Nature Publishing Group, 2016.
ista: Schwarz J, Bierbaum V, Merrin J, Frank T, Hauschild R, Bollenbach MT, Tay
S, Sixt MK, Mehling M. 2016. A microfluidic device for measuring cell migration
towards substrate bound and soluble chemokine gradients. Scientific Reports. 6,
36440.
mla: Schwarz, Jan, et al. “A Microfluidic Device for Measuring Cell Migration towards
Substrate Bound and Soluble Chemokine Gradients.” Scientific Reports, vol.
6, 36440, Nature Publishing Group, 2016, doi:10.1038/srep36440.
short: J. Schwarz, V. Bierbaum, J. Merrin, T. Frank, R. Hauschild, M.T. Bollenbach,
S. Tay, M.K. Sixt, M. Mehling, Scientific Reports 6 (2016).
date_created: 2018-12-11T11:50:27Z
date_published: 2016-11-07T00:00:00Z
date_updated: 2025-09-22T09:56:13Z
day: '07'
ddc:
- '579'
department:
- _id: MiSi
- _id: NanoFab
- _id: Bio
- _id: ToBo
doi: 10.1038/srep36440
ec_funded: 1
external_id:
isi:
- '000387118300001'
file:
- access_level: open_access
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:09:32Z
date_updated: 2018-12-12T10:09:32Z
file_id: '4756'
file_name: IST-2017-744-v1+1_srep36440.pdf
file_size: 2353456
relation: main_file
file_date_updated: 2018-12-12T10:09:32Z
has_accepted_license: '1'
intvolume: ' 6'
isi: 1
language:
- iso: eng
month: '11'
oa: 1
oa_version: Published Version
project:
- _id: 25A603A2-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '281556'
name: Cytoskeletal force generation and force transduction of migrating leukocytes
- _id: 25A8E5EA-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: Y 564-B12
name: Cytoskeletal force generation and force transduction of migrating leukocytes
publication: Scientific Reports
publication_status: published
publisher: Nature Publishing Group
publist_id: '6204'
pubrep_id: '744'
quality_controlled: '1'
scopus_import: '1'
status: public
title: A microfluidic device for measuring cell migration towards substrate bound
and soluble chemokine gradients
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: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 6
year: '2016'
...
---
_id: '1321'
abstract:
- lang: eng
text: Most migrating cells extrude their front by the force of actin polymerization.
Polymerization requires an initial nucleation step, which is mediated by factors
establishing either parallel filaments in the case of filopodia or branched filaments
that form the branched lamellipodial network. Branches are considered essential
for regular cell motility and are initiated by the Arp2/3 complex, which in turn
is activated by nucleation-promoting factors of the WASP and WAVE families. Here
we employed rapid amoeboid crawling leukocytes and found that deletion of the
WAVE complex eliminated actin branching and thus lamellipodia formation. The cells
were left with parallel filaments at the leading edge, which translated, depending
on the differentiation status of the cell, into a unipolar pointed cell shape
or cells with multiple filopodia. Remarkably, unipolar cells migrated with increased
speed and enormous directional persistence, while they were unable to turn towards
chemotactic gradients. Cells with multiple filopodia retained chemotactic activity
but their migration was progressively impaired with increasing geometrical complexity
of the extracellular environment. These findings establish that diversified leading
edge protrusions serve as explorative structures while they slow down actual locomotion.
acknowledged_ssus:
- _id: SSU
acknowledgement: "This work was supported by the German Research Foundation (DFG)
Priority Program SP 1464 to T.E.B.S. and M.S., and European Research Council (ERC
GA 281556) and Human Frontiers Program grants to M.S.\r\nService Units of IST Austria
for excellent technical support."
article_processing_charge: No
article_type: original
author:
- first_name: Alexander F
full_name: Leithner, Alexander F
id: 3B1B77E4-F248-11E8-B48F-1D18A9856A87
last_name: Leithner
orcid: 0000-0002-1073-744X
- first_name: Alexander
full_name: Eichner, Alexander
id: 4DFA52AE-F248-11E8-B48F-1D18A9856A87
last_name: Eichner
- first_name: Jan
full_name: Müller, Jan
id: AD07FDB4-0F61-11EA-8158-C4CC64CEAA8D
last_name: Müller
- first_name: Anne
full_name: Reversat, Anne
id: 35B76592-F248-11E8-B48F-1D18A9856A87
last_name: Reversat
orcid: 0000-0003-0666-8928
- first_name: Markus
full_name: Brown, Markus
id: 3DAB9AFC-F248-11E8-B48F-1D18A9856A87
last_name: Brown
- first_name: Jan
full_name: Schwarz, Jan
id: 346C1EC6-F248-11E8-B48F-1D18A9856A87
last_name: Schwarz
- first_name: Jack
full_name: Merrin, Jack
id: 4515C308-F248-11E8-B48F-1D18A9856A87
last_name: Merrin
orcid: 0000-0001-5145-4609
- first_name: David
full_name: De Gorter, David
last_name: De Gorter
- first_name: Florian
full_name: Schur, Florian
id: 48AD8942-F248-11E8-B48F-1D18A9856A87
last_name: Schur
orcid: 0000-0003-4790-8078
- first_name: Jonathan
full_name: Bayerl, Jonathan
last_name: Bayerl
- first_name: Ingrid
full_name: De Vries, Ingrid
id: 4C7D837E-F248-11E8-B48F-1D18A9856A87
last_name: De Vries
- first_name: Stefan
full_name: Wieser, Stefan
id: 355AA5A0-F248-11E8-B48F-1D18A9856A87
last_name: Wieser
orcid: 0000-0002-2670-2217
- first_name: Robert
full_name: Hauschild, Robert
id: 4E01D6B4-F248-11E8-B48F-1D18A9856A87
last_name: Hauschild
orcid: 0000-0001-9843-3522
- first_name: Frank
full_name: Lai, Frank
last_name: Lai
- first_name: Markus
full_name: Moser, Markus
last_name: Moser
- first_name: Dontscho
full_name: Kerjaschki, Dontscho
last_name: Kerjaschki
- first_name: Klemens
full_name: Rottner, Klemens
last_name: Rottner
- first_name: Victor
full_name: Small, Victor
last_name: Small
- first_name: Theresia
full_name: Stradal, Theresia
last_name: Stradal
- first_name: Michael K
full_name: Sixt, Michael K
id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
last_name: Sixt
orcid: 0000-0002-6620-9179
citation:
ama: Leithner AF, Eichner A, Müller J, et al. Diversified actin protrusions promote
environmental exploration but are dispensable for locomotion of leukocytes. Nature
Cell Biology. 2016;18:1253-1259. doi:10.1038/ncb3426
apa: Leithner, A. F., Eichner, A., Müller, J., Reversat, A., Brown, M., Schwarz,
J., … Sixt, M. K. (2016). Diversified actin protrusions promote environmental
exploration but are dispensable for locomotion of leukocytes. Nature Cell Biology.
Nature Publishing Group. https://doi.org/10.1038/ncb3426
chicago: Leithner, Alexander F, Alexander Eichner, Jan Müller, Anne Reversat, Markus
Brown, Jan Schwarz, Jack Merrin, et al. “Diversified Actin Protrusions Promote
Environmental Exploration but Are Dispensable for Locomotion of Leukocytes.” Nature
Cell Biology. Nature Publishing Group, 2016. https://doi.org/10.1038/ncb3426.
ieee: A. F. Leithner et al., “Diversified actin protrusions promote environmental
exploration but are dispensable for locomotion of leukocytes,” Nature Cell
Biology, vol. 18. Nature Publishing Group, pp. 1253–1259, 2016.
ista: Leithner AF, Eichner A, Müller J, Reversat A, Brown M, Schwarz J, Merrin J,
De Gorter D, Schur FK, Bayerl J, de Vries I, Wieser S, Hauschild R, Lai F, Moser
M, Kerjaschki D, Rottner K, Small V, Stradal T, Sixt MK. 2016. Diversified actin
protrusions promote environmental exploration but are dispensable for locomotion
of leukocytes. Nature Cell Biology. 18, 1253–1259.
mla: Leithner, Alexander F., et al. “Diversified Actin Protrusions Promote Environmental
Exploration but Are Dispensable for Locomotion of Leukocytes.” Nature Cell
Biology, vol. 18, Nature Publishing Group, 2016, pp. 1253–59, doi:10.1038/ncb3426.
short: A.F. Leithner, A. Eichner, J. Müller, A. Reversat, M. Brown, J. Schwarz,
J. Merrin, D. De Gorter, F.K. Schur, J. Bayerl, I. de Vries, S. Wieser, R. Hauschild,
F. Lai, M. Moser, D. Kerjaschki, K. Rottner, V. Small, T. Stradal, M.K. Sixt,
Nature Cell Biology 18 (2016) 1253–1259.
corr_author: '1'
date_created: 2018-12-11T11:51:21Z
date_published: 2016-10-24T00:00:00Z
date_updated: 2026-06-18T22:30:13Z
day: '24'
ddc:
- '570'
department:
- _id: MiSi
- _id: NanoFab
- _id: Bio
doi: 10.1038/ncb3426
ec_funded: 1
external_id:
isi:
- '000387165600018'
file:
- access_level: open_access
checksum: e1411cb7c99a2d9089c178a6abef25e7
content_type: application/pdf
creator: dernst
date_created: 2020-05-14T16:33:46Z
date_updated: 2020-07-14T12:44:43Z
file_id: '7844'
file_name: 2018_NatureCell_Leithner.pdf
file_size: 4433280
relation: main_file
file_date_updated: 2020-07-14T12:44:43Z
has_accepted_license: '1'
intvolume: ' 18'
isi: 1
language:
- iso: eng
month: '10'
oa: 1
oa_version: Submitted Version
page: 1253 - 1259
project:
- _id: 25A603A2-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '281556'
name: Cytoskeletal force generation and force transduction of migrating leukocytes
publication: Nature Cell Biology
publication_status: published
publisher: Nature Publishing Group
publist_id: '5949'
quality_controlled: '1'
related_material:
record:
- id: '323'
relation: dissertation_contains
status: public
scopus_import: '1'
status: public
title: Diversified actin protrusions promote environmental exploration but are dispensable
for locomotion of leukocytes
tmp:
image: /images/cc_by_nc_sa.png
legal_code_url: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode
name: Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC
BY-NC-SA 4.0)
short: CC BY-NC-SA (4.0)
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 18
year: '2016'
...