Collective Excitation Dynamics in Molecular Aggregates

Mats Dahlbom

Collective Excitation Dynamics in Molecular Aggregates

Mats Dahlbom

Kemisk fysik

Forskningsoutput: Avhandling › Doktorsavhandling (sammanläggning)

Sammanfattning

Popular Abstract in Swedish
Den här avhandlingen är framlagd i ämnet kemisk fysik. Kemisk fysik är ett mycket stort forskningsområde, som innefattar fenomen allt ifrån vibrationer i molekylära bindningar till betydligt större fenomen, som till exempel energi och elektrontransport i den naturliga fotosyntesen. Fotosyntesen är naturens mest betydelsefulla process. Den driver i princip alla växter, som i sin tur är föda för alla jordens djur, inklusive oss människor. Detta är något vi alla känner väl till ifrån skolan och det är säkerligen ingen överraskning för någon att denna process till stora delar är mycket effektiv. Det är dock inte bara gröna växter som utnyttjar fotosyntesen utan även många planktonarter och bakterier nyttjar den. De initiala stegen i fotosyntesen kan i princip beskrivas som en fler-stegs process; (i) infångande av soljus, (ii) transport av den infångade energin och slutligen (iii) den av energin initierade transport av en elektron genom cellmembranet. Vi har studerat egenskaperna hos de grundläggande energipaket som antennsystemen innehåller efter att de har blivit belysta med ljus. Dessa ljusinsamlande antenner består av pigment molekyler. På grund av den starka kopplingen mellan dessa byggstenar så kommer energipaketen att vara ”utsmetade” ¨over en betydande del av antennen. Den här avhandlingen berör de första momenten av energitransporten i den naturliga fotosyntesen och den teoretiska beskrivningen av de grundläggande excitationernas egenskaper och dynamik i antennkomplexen. Avhandlingen innehaller lika delar metod utveckling och applikationer av dessa metoder på fotosyntetiska antenn och modell-system.

Originalspråk	engelska
Kvalifikation	Doktor
Tilldelande institution	Kemisk fysik
Handledare	[unknown], [unknown], handledare, Extern person
Tilldelningsdatum	2002 feb. 1
Förlag	Department of Chemical Physics, Lund University
ISBN (tryckt)	91-7874-174-2
Status	Published - 2002

Bibliografisk information

Defence details

Date: 2002-02-01
Time: 14:15
Place: Lecture Hall B, Chemisty Center, Getingevägen 60, Lund, Sweden

External reviewer(s)

Name: Knoester, J.
Title: Professor
Affiliation: Institute for Theoretical Physics,University of Groningen, Nijenborgh 4, NL-9747 AG Groningen, The Netherlands.

---

Article: Exciton-Wave Packet Dynamics in Molecular Aggregates Studied with Pump-ProbeSpectroscopy, J. Phys. Chem. B 2000, 104, 3976-3983Mats Dahlbom, Tatsuya Minami, Vladimir Chernyak, Tonu Pullerits,Villy Sundström, and Shaul Mukamel

Article: Exciton Delocalization in the B850 Light-Harvesting Complex: Comparison of Different Measures,J. Phys. Chem. B 2001, 105, 5515-5524Mats Dahlbom, Tonu Pullerits,Shaul Mukamel, and Villy Sundström

Article: Collective Excitation Dynamics in Molecular Aggregates: Exciton Relaxation, Self-trapping and Polaron Formation.In press, Proceedings of BioPhysical Chemistry 2001.Mats Dahlbom, Wichard Beenken, Villy Sundström, Tonu Pullerits

Article: Collective Excitation Dynamics and Polaron Formation in Molecular AggregatesSubmitted to Phys. Rev. Lett. 2001.Mats Dahlbom, Wichard Beenken, Villy Sundström, Tonu Pullerits

Article: Potential Surfaces and Delocalization of Excitons in Dimers.Manuscript, To be submitted to J. Chem. Phys.Wichard Beenken, Mats Dahlbom, Pär Kjellberg, Villy Sundström, Tonu Pullerits

Article: Polaron Transport and Directed Energy Funnelling in Light-Harvesting Pigment-Protein Complexes.Manuscript, To be submitted to J. Phys. Chem. B.Mats Dahlbom, Wichard Beenken, Villy Sundström, Tonu Pullerits

The information about affiliations in this record was updated in December 2015.
The record was previously connected to the following departments: Chemical Physics (S) (011001060)

Ämnesklassifikation (UKÄ)

Atom- och molekylfysik och optik (Här ingår: Kemisk fysik, kvantoptik)

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@phdthesis{4aeefee1b3fe4b80ab45adfbc0557174,

title = "Collective Excitation Dynamics in Molecular Aggregates",

abstract = "The aim of this thesis is to study collective excitation dynamics in molecular aggregates. Half of the work presented here is method development and the remainder is application of these methods to several di.erent molecular aggregates. In the first two papers, the pump-probe signal was derived using the Green function approach of the optical response functions and formulated in the Doorway-Window representation. This method was applied to the B850 aggregate of the purple bacteria, Rhodobacter sphaeroides and compared with recent experimental results. The steady-state absorption as well as the thermalized pump-probe spectra were in good agreement with the experimental data for a given parameter set. Furthermore, the temporal evolution of the transient absorption spectra was also well described for the same parameter set. The concept of exciton delocalization was addressed using this method and several theoretical estimations were discussed and compared with each other. Furthermore, the time evolution and dependency of the initial preparation were studied and compared with different experimental techniques. In the second part, the excitation dynamics in molecular aggregates was studied using the surface hopping technique. This method incorporates coupling to the nuclear coordinates explicitly and treats the nuclear system classically. The third and the forth paper included in this thesis, develops the surface hopping method and the simulations were made for model aggregates. The fifth paper introduces an analytical version of the previously presented surface hopping model. In the last included paper, this method was applied to the B850 antenna complex of Rhodobacter sphaeroides with parameters extracted from a realistic spectral density distribution. A number of explicit harmonic oscillators were used to describe the molecular vibrations. Special attention was directed to the nonlinear dependence of the excitonic potential energy surfaces and the exciton-vibrational feedback term. Polaron formation, migration and self-trapping was shown to occur for certain parameter sets.",

keywords = "Chemistry, Kemi, Fysik, Physics, computational methods, photosynthesis, femtosecond spectroscopy, Exciton, Polaron",

author = "Mats Dahlbom",

note = "Defence details Date: 2002-02-01 Time: 14:15 Place: Lecture Hall B, Chemisty Center, Getingev{\"a}gen 60, Lund, Sweden External reviewer(s) Name: Knoester, J. Title: Professor Affiliation: Institute for Theoretical Physics,University of Groningen, Nijenborgh 4, NL-9747 AG Groningen, The Netherlands. --- Article: Exciton-Wave Packet Dynamics in Molecular Aggregates Studied with Pump-ProbeSpectroscopy, J. Phys. Chem. B 2000, 104, 3976-3983Mats Dahlbom, Tatsuya Minami, Vladimir Chernyak, Tonu Pullerits,Villy Sundstr{\"o}m, and Shaul Mukamel Article: Exciton Delocalization in the B850 Light-Harvesting Complex: Comparison of Different Measures,J. Phys. Chem. B 2001, 105, 5515-5524Mats Dahlbom, Tonu Pullerits,Shaul Mukamel, and Villy Sundstr{\"o}m Article: Collective Excitation Dynamics in Molecular Aggregates: Exciton Relaxation, Self-trapping and Polaron Formation.In press, Proceedings of BioPhysical Chemistry 2001.Mats Dahlbom, Wichard Beenken, Villy Sundstr{\"o}m, Tonu Pullerits Article: Collective Excitation Dynamics and Polaron Formation in Molecular AggregatesSubmitted to Phys. Rev. Lett. 2001.Mats Dahlbom, Wichard Beenken, Villy Sundstr{\"o}m, Tonu Pullerits Article: Potential Surfaces and Delocalization of Excitons in Dimers.Manuscript, To be submitted to J. Chem. Phys.Wichard Beenken, Mats Dahlbom, P{\"a}r Kjellberg, Villy Sundstr{\"o}m, Tonu Pullerits Article: Polaron Transport and Directed Energy Funnelling in Light-Harvesting Pigment-Protein Complexes.Manuscript, To be submitted to J. Phys. Chem. B.Mats Dahlbom, Wichard Beenken, Villy Sundstr{\"o}m, Tonu Pullerits The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)",

year = "2002",

language = "English",

isbn = "91-7874-174-2",

publisher = "Department of Chemical Physics, Lund University",

type = "Doctoral Thesis (compilation)",

school = "Chemical Physics",

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TY - THES

T1 - Collective Excitation Dynamics in Molecular Aggregates

AU - Dahlbom, Mats

N1 - Defence details Date: 2002-02-01 Time: 14:15 Place: Lecture Hall B, Chemisty Center, Getingevägen 60, Lund, Sweden External reviewer(s) Name: Knoester, J. Title: Professor Affiliation: Institute for Theoretical Physics,University of Groningen, Nijenborgh 4, NL-9747 AG Groningen, The Netherlands. --- Article: Exciton-Wave Packet Dynamics in Molecular Aggregates Studied with Pump-ProbeSpectroscopy, J. Phys. Chem. B 2000, 104, 3976-3983Mats Dahlbom, Tatsuya Minami, Vladimir Chernyak, Tonu Pullerits,Villy Sundström, and Shaul Mukamel Article: Exciton Delocalization in the B850 Light-Harvesting Complex: Comparison of Different Measures,J. Phys. Chem. B 2001, 105, 5515-5524Mats Dahlbom, Tonu Pullerits,Shaul Mukamel, and Villy Sundström Article: Collective Excitation Dynamics in Molecular Aggregates: Exciton Relaxation, Self-trapping and Polaron Formation.In press, Proceedings of BioPhysical Chemistry 2001.Mats Dahlbom, Wichard Beenken, Villy Sundström, Tonu Pullerits Article: Collective Excitation Dynamics and Polaron Formation in Molecular AggregatesSubmitted to Phys. Rev. Lett. 2001.Mats Dahlbom, Wichard Beenken, Villy Sundström, Tonu Pullerits Article: Potential Surfaces and Delocalization of Excitons in Dimers.Manuscript, To be submitted to J. Chem. Phys.Wichard Beenken, Mats Dahlbom, Pär Kjellberg, Villy Sundström, Tonu Pullerits Article: Polaron Transport and Directed Energy Funnelling in Light-Harvesting Pigment-Protein Complexes.Manuscript, To be submitted to J. Phys. Chem. B.Mats Dahlbom, Wichard Beenken, Villy Sundström, Tonu Pullerits The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)

PY - 2002

Y1 - 2002

N2 - The aim of this thesis is to study collective excitation dynamics in molecular aggregates. Half of the work presented here is method development and the remainder is application of these methods to several di.erent molecular aggregates. In the first two papers, the pump-probe signal was derived using the Green function approach of the optical response functions and formulated in the Doorway-Window representation. This method was applied to the B850 aggregate of the purple bacteria, Rhodobacter sphaeroides and compared with recent experimental results. The steady-state absorption as well as the thermalized pump-probe spectra were in good agreement with the experimental data for a given parameter set. Furthermore, the temporal evolution of the transient absorption spectra was also well described for the same parameter set. The concept of exciton delocalization was addressed using this method and several theoretical estimations were discussed and compared with each other. Furthermore, the time evolution and dependency of the initial preparation were studied and compared with different experimental techniques. In the second part, the excitation dynamics in molecular aggregates was studied using the surface hopping technique. This method incorporates coupling to the nuclear coordinates explicitly and treats the nuclear system classically. The third and the forth paper included in this thesis, develops the surface hopping method and the simulations were made for model aggregates. The fifth paper introduces an analytical version of the previously presented surface hopping model. In the last included paper, this method was applied to the B850 antenna complex of Rhodobacter sphaeroides with parameters extracted from a realistic spectral density distribution. A number of explicit harmonic oscillators were used to describe the molecular vibrations. Special attention was directed to the nonlinear dependence of the excitonic potential energy surfaces and the exciton-vibrational feedback term. Polaron formation, migration and self-trapping was shown to occur for certain parameter sets.

AB - The aim of this thesis is to study collective excitation dynamics in molecular aggregates. Half of the work presented here is method development and the remainder is application of these methods to several di.erent molecular aggregates. In the first two papers, the pump-probe signal was derived using the Green function approach of the optical response functions and formulated in the Doorway-Window representation. This method was applied to the B850 aggregate of the purple bacteria, Rhodobacter sphaeroides and compared with recent experimental results. The steady-state absorption as well as the thermalized pump-probe spectra were in good agreement with the experimental data for a given parameter set. Furthermore, the temporal evolution of the transient absorption spectra was also well described for the same parameter set. The concept of exciton delocalization was addressed using this method and several theoretical estimations were discussed and compared with each other. Furthermore, the time evolution and dependency of the initial preparation were studied and compared with different experimental techniques. In the second part, the excitation dynamics in molecular aggregates was studied using the surface hopping technique. This method incorporates coupling to the nuclear coordinates explicitly and treats the nuclear system classically. The third and the forth paper included in this thesis, develops the surface hopping method and the simulations were made for model aggregates. The fifth paper introduces an analytical version of the previously presented surface hopping model. In the last included paper, this method was applied to the B850 antenna complex of Rhodobacter sphaeroides with parameters extracted from a realistic spectral density distribution. A number of explicit harmonic oscillators were used to describe the molecular vibrations. Special attention was directed to the nonlinear dependence of the excitonic potential energy surfaces and the exciton-vibrational feedback term. Polaron formation, migration and self-trapping was shown to occur for certain parameter sets.

KW - Chemistry

KW - Kemi

KW - Fysik

KW - Physics

KW - computational methods

KW - photosynthesis

KW - femtosecond spectroscopy

KW - Exciton

KW - Polaron

M3 - Doctoral Thesis (compilation)

SN - 91-7874-174-2

PB - Department of Chemical Physics, Lund University

ER -

Collective Excitation Dynamics in Molecular Aggregates

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Ämnesklassifikation (UKÄ)

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