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Ordered electronic phases in low dimensional superconductors

English title Ordered electronic phases in low dimensional superconductors
Applicant Renner Christoph
Number 144139
Funding scheme Project funding (Div. I-III)
Research institution Département de Physique de la Matière Condensée Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Condensed Matter Physics
Start/End 01.11.2012 - 31.10.2015
Approved amount 227'954.00
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Keywords (9)

Stripes; Correlated electrons; Superconductivity; Graphite intercalated compounds; Scanning tunneling spectroscopy; Scanning tunneling microscopy; Transition metal dichalcogenides; Charge density waves; Quasiparticle interference imaging

Lay Summary (English)

Lead
Lay summary

Electronic charge and spin segregation into one-directional density waves, called stripes, is ubiquitous in copper oxide high temperature superconductor (HTS). The interplay between these stripes, which are a particular form of charge density wave (CDW), and superconductivity has been a long standing research focus, especially in compounds of reduced dimensionality. Among the underlying questions is whether these stripes play a role or not in the occurrence of superconductivity at high temperature.

CDWs remain matter of heated debates and subject to experimental scrutiny in the context of high temperature superconductivity. We have recently observed charge stripes in CaC6 and 1T-CuxTiSe2, two low temperature superconductors. These materials are not only much less complex than HTS, they also happen to exhibit the highest superconducting transition temperature measured to date in their respective class of materials. They appear therefore as perfect candidates to investigate possible connections between superconductivity and stripes. The aim of this project is to contribute to the understanding and detailed characterization of the stripe phase. Open questions include the size and symmetry of the energy gap in the electronic excitation spectrum, and the coexistence or not of stripes and superconductivity. We shall address these issues by exploiting the latest developments in scanning probe microscopy and spectroscopy, especially quasiparticle interference imaging and combined scanning tunneling microscopy and atomic force microscopy.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Scanning tunneling microscopy of the charge density wave in 1T-TiSe2 in the presence of single atom defects
Novello A. M., Hildebrand B., Scarfato A., Didiot C., Monney G., Ubaldini A., Berger H., Bowler D. R., Aebi P., Renner Ch. (2015), Scanning tunneling microscopy of the charge density wave in 1T-TiSe2 in the presence of single atom defects, in PHYSICAL REVIEW B, 92(8), 081101-1.
Doping Nature of Native Defects in 1T-TiSe2
Hildebrand B., Didiot C., Novello A. M., Monney G., Scarfato A., Ubaldini A., Berger H., Bowler D. R., Renner C., Aebi P. (2014), Doping Nature of Native Defects in 1T-TiSe2, in PHYSICAL REVIEW LETTERS, 112(19), 197001-1-197001-5.

Collaboration

Group / person Country
Types of collaboration
Dr. M. Ellerby, London Centre for Nanotechnology, University College London Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Prof. Radovan Cerny, DPMC, University of geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Prof. Philipp Aebi, FRIMAT, University of Fribourg Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Alberto Ubaldini, DPMC, University of Geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. David Bowler, London Centre for Nanotechnology, University College London Great Britain and Northern Ireland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Helmut Berger, EPFL Switzerland (Europe)
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
M2S Poster Charge density waves and superconductivity in CuxTiSe2 23.08.2015 Geneva, Switzerland Novello Anna Maria; Renner Christoph;
M2S Talk given at a conference New light on the subgap states seen by STM in YBCO 23.08.2015 Geneva, Switzerland Renner Christoph;
Superstripes 2015 Talk given at a conference On the vortex core states seen by STM in YBa2Cu3O7-d 16.06.2015 Ischia, Italy Renner Christoph;
STM on unconventional superconductors, NLSC Talk given at a conference Nematic and stripe charge order in high temperature and “conventional” superconductors 25.10.2014 Beijing, China Renner Christoph;
Superstripes 2014 Talk given at a conference Chiral and stripe charge order in 1T-CuxTiSe2 25.07.2014 Erice, Italy Renner Christoph;
5th Young Researcher Meeting Poster Charge Density Waves in CuxTiSe2 14.07.2014 Trieste, Italy Novello Anna Maria;
SPS Annual meeting Poster Charge density waves in CuxTiSe2 30.06.2014 Fribourg, Switzerland Novello Anna Maria; Renner Christoph;
Science through Scanning Probe Microscopy Talk given at a conference Charge Density Waves in CuxTiSe2 12.12.2013 Bologna, Italy Novello Anna Maria;
Vortex VIII Poster Charge density waves and superconductivity in CuxTiSe2 21.09.2013 Rhodes, Greece Novello Anna Maria;
2013 Swiss Workshop on Materials with Novel Electronic Properties Talk given at a conference Charge Density Waves and Superconductivity in CuxTiSe2 24.06.2013 Les Diablerets, Switzerland Novello Anna Maria; Renner Christoph;
Heinrich Rohrer symposium Talk given at a conference Peeking at high temperature superconductors with a tip 01.11.2012 ETHZ, Zürich, , Switzerland Renner Christoph;


Associated projects

Number Title Start Funding scheme
147607 Electronic properties of new atomically thin semiconductors 01.01.2014 Sinergia
162517 Electron matter in unconventional layered superconductors 01.11.2015 Project funding (Div. I-III)
133777 Scanning probe microscopy and spectroscopy of nanoscale materials and devices 01.01.2011 R'EQUIP

Abstract

Electronic charge and spin segregation into one-directional density waves called stripes is ubiquitous in high temperature superconductor (HTS) copper oxides, in colossal magnetoresistance (CMR) manganese oxides and several other low dimensional electronic oxide materials. Stripes are a particular form of charge density wave (CDW). The interplay between CDWs and superconductivity has been a long standing research focus for a range of superconducting materials whose electronic systems exhibit a reduced dimensionality. The role CDWs play in the occurrence of high temperature superconductivity remains matter of heated debates and subject to experimental scrutiny. Furthermore, fundamental questions about the mechanisms leading to CDW and stripe formation remain open. The challenge of solving the puzzle of "high" temperature superconductivity observed in cuprates, and more recently in iron pnictides, has been driving remarkable developments in theory and experimental techniques, especially scanning tunneling microscopy (STM) and photoemission. However, progresses in STM did so far mostly benefit HTS copper oxides and a range of superconducting materials discovered in their wake (e.g. pnictides and oxichlorides), as well as topological insulators. These materials have attracted much of the community’s attention in recent times. Our three year project is to initiate a new effort following the recent discoveries of charge stripes in a graphite intercalated compound CaC6 and 1T-CuxTiSe2, two low-Tc layered superconductors. Interestingly, they show, along with charge stripes, the highest superconducting transition temperature measured to date in their class. A number of novel experimental findings have brought these materials back into the spotlight. These include significant increase of the superconducting transition temperature, chiral and stripe CDWs, an exciton ground state and remarkable similarities of the CDW and HTS pseudogap phases as observed by ARPES. Our project is to deploy modern scanning probe expertise, especially quasiparticle interference imaging, to contribute to the detailed characterization and understanding of these correlated electron phases and their interaction.
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