Publications

Highlights

(For a full list see below or go to Google Scholar, ResearcherID)

Creating better superconductors by periodic nanopatterning

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

arXiv:1704.06805 (2017)

Poor electronic screening in lightly doped Mott insulators observed with scanning tunneling microscopy

We develop a simple model to interpret STM results on lightly doped Mott insulators, and find that the effective Mott gap measured by STM correspons to the one measured with other techniques when taking into account the poor electronic screeing.

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

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

Nature Physics 13, 21 (2017)

See also Leiden University news by Erik Arends, Phys.org

Identifying the fingerprint of antiferromagnetic spin fluctuations in iron pnictide superconductors

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

Nature Physics 11, 177 (2015)

See also Cornell Chronicle by Anne Ju, Phys.org

Imaging Cooper pairing of heavy fermions in CeCoIn5

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

Nature Physics 9, 468 (2013)

Featured in ‘News and Views’ by L Taillefer

See also Phys.org, DoE headliner

Formation of heavy d-electron quasiparticles in Sr3Ru2O7

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)

Anisotropic impurity states, quasiparticle scattering and nematic transport in underdoped Ca(Fe1−xCox)2As2

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

Nature Physics 9, 220 (2013)

See also Tech Connect by Jennifer Rocha, Phys.org by Bill Steele

Anisotropic energy gaps of iron-based superconductivity from intraband quasiparticle interference in LiFeAs

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

Science 336, 563 (2012)

See also Cornell Cornincle by Bill Steele, Eureka Alert

Nematic electronic structure in the “parent” state of the iron-based superconductor Ca(Fe1−xCox)2As2

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

Science 327, 181 (2010)

Featured in a ‘Perspective’ by E Fradkin & SA Kivelson

See also Article on NewScientist by Colin Barras

Tunable self-assembly of one-dimensional nanostructures with orthogonal directions

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

Robust procedure for creating and characterizing the atomic structure of scanning tunneling microscope tips
S Tewari, KM Bastiaans, MP Allan, JM van Ruitenbeek
arXiv:1705.08796 (2017)

Creating better superconductors by periodic nanopatterning
MP Allan, MH Fischer, O Ostojic, A Andringa
arXiv:1704.06805 (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)

Fermi surface and van Hove singularities in the itinerant metamagnet Sr 3Ru2O7
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)