Presentation is loading. Please wait.

Presentation is loading. Please wait.

Molecular Transport Group

Published byKristian Hunter Modified over 6 years ago

Similar presentations

Presentation on theme: "Molecular Transport Group"— Presentation transcript:

1 Molecular Transport Group
I Héctor Vázquez  Institute of Physics, Academy of Sciences of the Czech Republic. Solid State Physics division, Dept. of Thin Films and Nanostructures.

2 Molecular-scale electronic circuits
Miniaturization of microelectronic components. The flow of an electronic current is often determined by the narrowest part of the circuit. Molecules as the key electronic components. Importance of physical and chemical details of metal-molecule-metal interface. Quantum effects play an essential role. Possible future applications but also focus of fundamental science. Interdisciplinary character: physics, chemistry, materials science… J.C. Cuevas and E. Scheer, ‘Molecular Electronics: An Introduction to Theory and Experiment’, World Scientific Series in Nanotechnology and Nanoscience (2010) Kasper Moth-Poulsen, ‘Handbook of Single-Molecule Electronics’, Pan Stanford (2015).

3 Schematics of a single molecule circuit
Molecular backbone Conducting mechanism: tunneling, resonant transport, hopping Molecular quantum properties (eg. interference) Electrode Work function Energy level alignment Electronic coupling I Chemical linkers (end groups) Mechanical contact between metal and molecule Energy level alignment Electronic coupling Understanding and designing the different components of a single molecule circuit

4 Electron transport measurements
Made possible by advances in scanning probe methods. Most common techniques: STM/AFM methods in UHV at LT (~5K). Control of junction geometry. STM break-junction method. In solution and at room temperature. Thousands of measurements – conductance histograms. No Data Selection Traces

5 Simulations of electron transport across molecular junctions
Modeling of junction at the atomistic level (incl. quantum effects) is necessary. Ab-initio simulations: Density Functional Theory and Non-Equilibrium Green’s Functions. DFT: intractable problem of interacting electrons reduced to tractable problem of non-interacting electrons in an effective potential. Hohenberg–Kohn theorems (1964). Ground-state energy determined by electron density. Kohn–Sham approach (1965). Nobel prize in chemistry 1998: Kohn, Pople. Input: geometry guess and a few (reasonable) assumptions. Advantages: powerful and general, transferrable (parameter-free). Disadvantages: computationally expensive, small (idealized) systems.

6 Examples of molecular transport simulations from our group (1 of 2)
Conductance of different metal-molecule linkers Conductance of both ends of the molecular junction (in collab. with experiments) Proposal for a stable and highly-conducting platform Au-C Phys. Chem. Chem. Phys (2018) First study of the conductance of an antiaromatic molecule, with experimental and chemist collaborators Au-S Au-SMe ‎Nature Communications (2017)

7 Examples of molecular transport simulations from our group (2 of 2)
Constructive quantum interference: G2 > 2 G1 Interaction of tunneling electrons with vibrations on molecule: IETS. Mapping the spatial origin of the inelastic signal Nature Nanotechnology (2012) Phys. Rev. B (2016) , Phys. Rev. Lett (2017) Current-induced heating and cooling in carbene-based molecular circuits. Rates of energy exchange between tunneling electrons and vibrations. Cooling Heating Nanotechnology (2016), J. Phys. Chem. C (2016), Beilstein J. Nanotechnol (2017)

8 Group: who are we? Molecular Transport group: Independent research group interested in first-principles simulations of mechanical, electronic, and conducting properties of molecular junctions. Currently consists of 2 postdocs and 2 PhD students (1 of them shared). Funding: J.E. Purkyně Fellowship. Czech Science Foundation (GAČR). Marie Skłodowska-Curie postdoc fellowship. Inst. of Physics departmental funding. Héctor Vázquez Giuseppe Foti Enrique Montes Group webpage Narendra Arasu Martin Hládik

9 Are ab-initio transport simulations for you?
What you will do in the group: Develop and carry out a guided research program in molecular quantum transport. Perform and analyze electronic structure and transmission calculations. Prepare and write publications. Present results at international conferences. Useful knowledge / background for a PhD in single molecule transport simulations: Solid-state physics. Metals, bands, real-reciprocal space … Chemical physics. Energy levels, molecular orbitals, tight-binding method … Programming. FORTRAN, python, scripting, unix/linux environment … Other skills. Analytical thinking, perseverance, dynamism … Most important: interest, curiosity and motivation ! Take a look: Informal enquiries:

Download ppt "Molecular Transport Group"

Similar presentations

Introduction to Computational Chemistry NSF Computational Nanotechnology and Molecular Engineering Pan-American Advanced Studies Institutes (PASI) Workshop.

Introduction to Computational Chemistry NSF Computational Nanotechnology and Molecular Engineering Pan-American Advanced Studies Institutes (PASI) Workshop.
Scanning tunnelling spectroscopy

Scanning tunnelling spectroscopy
Modelling of Defects DFT and complementary methods

Modelling of Defects DFT and complementary methods
Quantum Theory of Solids

Quantum Theory of Solids
Dynamics of Vibrational Excitation in the C 60 - Single Molecule Transistor Aniruddha Chakraborty Department of Inorganic and Physical Chemistry Indian.

Dynamics of Vibrational Excitation in the C 60 - Single Molecule Transistor Aniruddha Chakraborty Department of Inorganic and Physical Chemistry Indian.
1 Molecular electronics: a new challenge for O(N) methods Roi Baer and Daniel Neuhauser (UCLA) Institute of Chemistry and Lise Meitner Center for Quantum.

1 Molecular electronics: a new challenge for O(N) methods Roi Baer and Daniel Neuhauser (UCLA) Institute of Chemistry and Lise Meitner Center for Quantum.
Stability analysis of metallic nanowires: Interplay of Rayleigh and Peierls Instabilities Daniel Urban and Hermann Grabertcond-mat/0307279 Jellium model:

Stability analysis of metallic nanowires: Interplay of Rayleigh and Peierls Instabilities Daniel Urban and Hermann Grabertcond-mat/ Jellium model:
Case Studies Class 5. Computational Chemistry Structure of molecules and their reactivities Two major areas –molecular mechanics –electronic structure.

Case Studies Class 5. Computational Chemistry Structure of molecules and their reactivities Two major areas –molecular mechanics –electronic structure.
Co-ordination & Harmonisation of Advanced e-Infrastructures for Research and Education Data Sharing Research Infrastructures – Proposal n. 306819 ABINIT,

Co-ordination & Harmonisation of Advanced e-Infrastructures for Research and Education Data Sharing Research Infrastructures – Proposal n ABINIT,
Theory of vibrationally inelastic electron transport through molecular bridges Martin Čížek Charles University Prague Michael Thoss, Wolfgang Domcke Technical.

Theory of vibrationally inelastic electron transport through molecular bridges Martin Čížek Charles University Prague Michael Thoss, Wolfgang Domcke Technical.
Molecular Modeling: Density Functional Theory C372 Introduction to Cheminformatics II Kelsey Forsythe.

Molecular Modeling: Density Functional Theory C372 Introduction to Cheminformatics II Kelsey Forsythe.
Lecture 9: Advanced DFT concepts: The Exchange-correlation functional and time-dependent DFT Marie Curie Tutorial Series: Modeling Biomolecules December.

Lecture 9: Advanced DFT concepts: The Exchange-correlation functional and time-dependent DFT Marie Curie Tutorial Series: Modeling Biomolecules December.
Density Functional Theory And Time Dependent Density Functional Theory

Density Functional Theory And Time Dependent Density Functional Theory
Lecture 8: Introduction to Density Functional Theory Marie Curie Tutorial Series: Modeling Biomolecules December 6-11, 2004 Mark Tuckerman Dept. of Chemistry.

Lecture 8: Introduction to Density Functional Theory Marie Curie Tutorial Series: Modeling Biomolecules December 6-11, 2004 Mark Tuckerman Dept. of Chemistry.
Calculation of Molecular Structures and Properties Molecular structures and molecular properties by quantum chemical methods Dr. Vasile Chiş Biomedical.

Calculation of Molecular Structures and Properties Molecular structures and molecular properties by quantum chemical methods Dr. Vasile Chiş Biomedical.
Molecular Modeling Fundamentals: Modus in Silico C372 Introduction to Cheminformatics II Kelsey Forsythe.

Molecular Modeling Fundamentals: Modus in Silico C372 Introduction to Cheminformatics II Kelsey Forsythe.
Lectures Introduction to computational modelling and statistics1 Potential models2 Density Functional.

Lectures Introduction to computational modelling and statistics1 Potential models2 Density Functional.
The Nuts and Bolts of First-Principles Simulation Durham, 6th-13th December 2001 25: DFT Plane Wave Pseudopotential versus Other Approaches CASTEP Developers’

The Nuts and Bolts of First-Principles Simulation Durham, 6th-13th December : DFT Plane Wave Pseudopotential versus Other Approaches CASTEP Developers’
Do molecular rectifiers exist? Fatemeh Gholamrezaie June 2006 RuGRuG.

Do molecular rectifiers exist? Fatemeh Gholamrezaie June 2006 RuGRuG.
Density Functional Theory (DFT) DFT is an alternative approach to the theory of electronic structure; electron density plays a central role in DFT. Why.

Density Functional Theory (DFT) DFT is an alternative approach to the theory of electronic structure; electron density plays a central role in DFT. Why.

Similar presentations

Ads by Google