Publications
Group highlights
(For a full list see below or go to Google Scholar, ResearcherID)
A first paper from the TBG collaboration is online, with beautiful data from the Baumberger group in Geneva, and great devices from the Efetov group at ICFO. We measured STM on the device.
S Lisi, X Lu, T Benschop, TA de Jong, Petr S, JR Duran, F Margot, I Cucchi, E Cappelli, A Hunter, A Tamai, V Kandyba, A Giampietri, A Barinov, J Jobst, V Stalman, M Leeuwenhoek, K Watanabe, T Taniguchi, L Rademaker, SJ van der Molen, MP Allan, DK Efetov, F Baumberger
We succeeded in measuring the superfluid density with atomic resolution on an unconventional superconductor! In contrast to expectations for conventional superconductors, we find that the superfluid densisty is strongly inhomogeneous in FeTe0.55Se0.45.
D Cho* & KM Bastiaans* & D Chatzopoulos*, GD Gu, MP Allan
We have imaged the doubling of the current noise due to Andreev reflections in a Josephson scanning tunneling microscope.
KM Bastiaans, D Cho, D Chatzopoulos, M Leeuwenhoek, C Koks, MP Allan
Phys. Rev. B 100, 104506 (2019)
Our first completely home-built STM is alive! And it has the world’s highest resonance frequency.
I Battisti, G Verdoes, K van Oosten, KM Bastiaans, and MP Allan
Rev. Sci. Instrum. 89, 123705 (2018)
Using our newly developed noise-spectroscopy technique we discover charge trapping in a cuprate high-temperature superconductor.
KM Bastiaans* & D Cho*, T Benschop, I Battisti, Y Huang, MS Golden, Q Dong, Y Jin, J Zaanen, MP Allan
Nature Physics 14, 1183 (2018)
Instrument details in Rev. Sci. Instrum. 89, 093709 (2018)
See also quantum universe (in dutch), Phys.org , Leiden University news, UvA news.
We introduce a platform for bringing new, device-based functionality to STM, with the goal of utilizing decades of progress in device engineering for the field of scanning probe.
M Leeuwenhoek, RA Norte, KM Bastiaans, Doohee Cho, I Battisti, YaM Blanter, S Gröblacher, MP Allan
Nanotechnology 30, 335702 (2019)
We propose an approach to transform a ‘pristine’ material into a better (meta-) superconductor by making use of modern fabrication techniques – designing and engineering the electronic properties of thin films via periodic patterning on the nanoscale.
MP Allan, MH Fischer, O Ostojic, A Andringa
We discover of electronic order, pseudo gap phase separation and an impurity-band Mott transition in an iridate compound, cuprate-style. Along the way, we gained unique knowledge on how a Mott state collapses.
I. Battisti* & K.M. Bastiaans*, V. Fedoseev, A. de la Torre, N. Iliopoulos, A. Tamai, E.C. Hunter, R.S. Perry, J. Zaanen, F. Baumberger, M.P. Allan
See also Leiden University news by Erik Arends, Phys.org
Both the density of states and the QPI dispersion of LiFeAs shows signatures of electron-boson coupling. Comparing these with fingerprints of different boson couplings to conclude that these signatures stem from AF spin fluctuations.
MP Allan* & Kyungmin Lee* & AW Rost*, MH Fischer, F Massee, K Kihou, C-H Lee, A Iyo, H Eisaki, T-M Chuang, AP Mackenzie, JC Davis, DJ Scalapino, E-A Kim
See also Cornell Chronicle by Anne Ju, Phys.org
The heavy Fermion superconductor CeCoIn5 has a d-wave gap with nodes along the (1,1) direction, as we find using QPI.
MP Allan* & F Massee*, DK Morr, J van Dyke, AW Rost, AP Mackenzie, C Petrovic, JC Davis
Featured in ‘News and Views’ by L Taillefer
See also Phys.org, DoE headliner
Using APRES, we find that the bands in Sr3Ru2O7 look more like in heavy fermion material than in a normal metal. We present a detailed investigation into the formation of this particular electronic structure.
MP Allan, A Tamai, E Rozbicki, MH Fischer, J Voss, PDC King, W Meevasana, S Thirupathaiah, E Rienks, J Fink, A Tennant, RS Perry, JF Mercure, MA Wang, J Lee, CJ Fennie, E-A Kim, MJ Lawler, KM Shen, AP Mackenzie, Z-X Shen, F Baumberger
New Journal of Physics 15, 063029 (2013)
We elucidate on the formation of the electronic nematic state in Co-CaFe2As2, finding that the Cobalt dopant atoms play a key role.
MP Allan, T-M Chuang, F Massee, Y Xie, N Ni, SL Bud’ko, GS Boebinger, Q Wang, DS Dessau, PC Canfield, MS Golden, JC Davis
See also Tech Connect by Jennifer Rocha, Phys.org by Bill Steele
In contrast to earlier photoemission reports, we show that the gaps in iron based superconductors are not isotropic but modulated with angle.
MP Allan⋆ & AW Rost⋆, AP Mackenzie, Y Xie, JC Davis, K Kihou, CH Lee, A Iyo, H Eisaki, T-M Chuang
See also Cornell Cornincle by Bill Steele, Eureka Alert
We discovered an electronic nematic in the iron based superconductor Co-CaFe2As2! This state is by now confirmed and quite well characterized by transport, photoemission, and more SI-STM experiments.
T-M Chuang* & MP Allan*, J Lee, Y Xie, N Ni, SL Bud’ko, GS Boebinger PC Canfield, JC Davis
Featured in a ‘Perspective’ by E Fradkin & SA Kivelson
See also Article on NewScientist by Colin Barras
Hexagonal boron nitride shows fancy superstructures on the Mo(111) surface.
MP Allan, S Berner, M Corso, T Greber, J Osterwalder
Nanoscale Research Letters 2, 94 (2007)
Full List
Multi-Atom Quasiparticle Scattering Interference for Superconductor Energy-Gap Symmetry Determination
R Sharma, A Kreisel, MA Sulangi, J Böker, A Kostin, MP Allan, H Eisaki, AE Böhmer, PC Canfield, I Eremin, JC Davis, PJ Hirschfeld, PO Sprau
arXiv:2005.05140
Modeling Green’s functions measurements with two-tip scanning tunneling microscopy
M Leeuwenhoek, S Gröblacher, MP Allan, YaM Blanter
arXiv:2005.00362
Direct evidence for flat bands in twisted bilayer graphene from nano-ARPES
S Lisi, X Lu, T Benschop, TA de Jong, Petr S, JR Duran, F Margot, I Cucchi, E Cappelli, A Hunter, A Tamai, V Kandyba, A Giampietri, A Barinov, J Jobst, V Stalman, M Leeuwenhoek, K Watanabe, T Taniguchi, L Rademaker, SJ van der Molen, MP Allan, DK Efetov, F Baumberger
arXiv:2002.02289
A strongly inhomogeneous superfluid in an iron-based superconductor
D Cho* & KM Bastiaans* & D Chatzopoulos*, GD Gu, MP Allan
Nature 571, 541 (2019)
Imaging doubled shot noise in a Josephson scanning tunneling microscope
KM Bastiaans, D Cho, D Chatzopoulos, M Leeuwenhoek, C Koks, MP Allan
Phys. Rev. B 100, 104506 (2019)
Definition of design guidelines, construction and performance of an ultra-stable scanning tunneling microscope for spectroscopic imaging
I Battisti, G Verdoes, K van Oosten, KM Bastiaans, and MP Allan
Rev. Sci. Instrum. 89, 123705 (2018)
Charge trapping and super-Poissonian noise centres in a cuprate superconductor
KM Bastiaans* & D Cho*, T Benschop, I Battisti, Y Huang, MS Golden, Q Dong, Y Jin, J Zaanen, MP Allan
Nature Physics 14, 1183 (2018)
Amplifier for scanning tunneling microscopy at MHz frequencies
KM Bastiaans, T Benschop, D Chatzopoulos, D Cho, Q Dong, Y Jin, MP Allan
Rev. Sci. Instrum. 89, 093709 (2018)
Nanofabricated tips as a platform for double-tip and device based scanning tunneling microscopy
M Leeuwenhoek, RA Norte, KM Bastiaans, Doohee Cho, I Battisti, YaM Blanter, S Gröblacher, MP Allan
Nanotechnology 30, 335702 (2019)
Revisiting quasiparticle scattering interference in high-temperature superconductors: the problem of narrow peaks
MA Sulangi, MP Allan, J Zaanen
PRB 96, 134507 (2017)
Robust procedure for creating and characterizing the atomic structure of scanning tunneling microscope tips
S Tewari, KM Bastiaans, MP Allan, JM van Ruitenbeek
Beilstein J. Nanotechnol. 8, 2389 (2017)
Creating better superconductors by periodic nanopatterning
MP Allan, MH Fischer, O Ostojic, A Andringa
SciPost Phys. 3, 010 (2017)
Poor electronic screening in lightly doped Mott insulators observed with scanning tunneling microscopy
I Battisti, V Fedoseev, KM Bastiaans, A de la Torre, RS Perry, F Baumberger, MP Allan
Phys. Rev. B 95, 235141, Editors’ suggestion (2017)
Universality of pseudo gap and emergent order in lightly doped Mott insulators
I. Battisti* & K.M. Bastiaans*, V. Fedoseev, A. de la Torre, N. Iliopoulos, A. Tamai, E.C. Hunter, R.S. Perry, J. Zaanen, F. Baumberger, M.P. Allan
Nature Physics 13, 21 (2017)
Identifying the fingerprint of antiferromagnetic spin fluctuations in iron pnictide superconductors
MP Allan* & Kyungmin Lee* & AW Rost*, MH Fischer, F Massee, K Kihou, C-H Lee, A Iyo, H Eisaki, T-M Chuang, AP Mackenzie, JC Davis, DJ Scalapino, E-A Kim
Nature Physics 11, 177 (2015)
Direct evidence for a magnetic f-electron mediated Cooper pairing mechanism of heavy fermion superconductivity in CeCoIn5
J Van Dyke, F Massee, MP Allan, JC Davis, C Petrovic, and DK Morr
PNAS 111, 11663 (2014)
Imaging Cooper pairing of heavy fermions in CeCoIn5
MP Allan* & F Massee*, DK Morr, J van Dyke, AW Rost, AP Mackenzie, C Petrovic, JC Davis
Nature Physics 9, 468 (2013)
Formation of heavy d-electron quasiparticles in Sr3Ru2O7
MP Allan, A Tamai, E Rozbicki, MH Fischer, J Voss, PDC King, W Meevasana, S Thirupathaiah, E Rienks, J Fink, A Tennant, RS Perry, JF Mercure, MA Wang, J Lee, CJ Fennie, E-A Kim, MJ Lawler, KM Shen, AP Mackenzie, Z-X Shen, F Baumberger
New Journal of Physics 15, 063029 (2013)
Anisotropic impurity states, quasiparticle scattering and nematic transport in underdoped Ca(Fe1−xCox)2As2
MP Allan, T-M Chuang, F Massee, Y Xie, N Ni, SL Bud’ko, GS Boebinger, Q Wang, DS Dessau, PC Canfield, MS Golden, JC Davis
Nature Physics 9, 220 (2013)
Anisotropic energy gaps of iron-based superconductivity from intraband quasiparticle interference in LiFeAs
MP Allan⋆ & AW Rost⋆, AP Mackenzie, Y Xie, JC Davis, K Kihou, CH Lee, A Iyo, H Eisaki, T-M Chuang
Science 336, 563 (2012)
How Kondo-holes create intense nanoscale heavy-fermion hybridization disorder
MH Hamidian, AR Schmidt, IA Firmo, MP Allan, P Bradley, JD Garrett, TJ Williams, GM Luke, Y Dubi, AV Balatsky, JC Davis
PNAS 108, 18233 (2011)
Nematic electronic structure in the “parent” state of the iron-based superconductor Ca(Fe1−xCox)2As2
T-M Chuang* & MP Allan*, J Lee, Y Xie, N Ni, SL Bud’ko, GS Boebinger PC Canfield, JC Davis
Science 327, 181 (2010)
Heavy d-electron quasiparticle interference and real-space electronic structure of Sr3Ru2O7
Jinho Lee* & M. P. Allan*, M. A.Wang, J. Farrell, S. A. Grigera, F. Baumberger, J. C. Davis and A. P. Mackenzie
Nature Physics 5, 800 (2009)
Fermi surface and van Hove singularities in the itinerant metamagnet Sr3Ru2O7
A Tamai, MP Allan, JF Mercure, W Meevasana, R Dunkel, DH Lu, RS Perry, AP Mackenzie, David J Singh, Z-X Shen, F Baumberger
Phys. Rev. Lett. 101, 026407 (2008)
Tunable self-assembly of one-dimensional nanostructures with orthogonal directions
MP Allan, S Berner, M Corso, T Greber, J Osterwalder
Nanoscale Research Letters 2, 94 (2007)
Photoelectron Diffraction for a Look inside Nanostructures
J Osterwalder, A Tamai, W Auwärter; MP Allan, T Greber
CHIMIA 11, 759 (2006)