Partially Coherent Charge Transport in DNA YiJing Yan Hong Kong University of Science and Technology ADMOL, 23 – 27 Feb. 2004, Dresden, Germany Collaborators: Prof. XinQi LI (Inst. Semiconductor, BeiJing) Dr. Houyu ZHANG (INFM Center S3, Italy) Mr. Ping HAN Acknowledgment: RGC-HK, NNSF-China
Partially Coherent Charge Transport in DNA. YiJing Yan Hong Kong University of Science and Technology. Collaborators: Prof. XinQi LI (Inst. Semiconductor, BeiJing) Dr. Houyu ZHANG (INFM Center S3, Italy) Mr. Ping HAN Acknowledgment: RGC-HK, NNSF-China. - PowerPoint PPT Presentation
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Partially Coherent Charge Transport in DNA
YiJing YanHong Kong University of Science and Technology
ADMOL, 23 – 27 Feb. 2004, Dresden, Germany
Collaborators:
Prof. XinQi LI (Inst. Semiconductor, BeiJing) Dr. Houyu ZHANG (INFM Center S3, Italy) Mr. Ping HAN
Acknowledgment: RGC-HK, NNSF-China
General IntroductionMotivation: bio-function & molecular device
Characteristics of nano-size: Partially coherent tunneling - Failure of (incoherence) Ohm’s law - Failure of (coherent) superexchange tunneling
0 2 4 6 8 10 12 14 160.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
our theoretical results
Giese et al, Nature (2001) 412:318experimental results
GTT...TGGGCAA...ACCC
log
(rel
ativ
e ra
te)
Numumber of AT-base pairs-4 -2 0 2 4
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
Porath et al, Nature (2000) 403:635
theoretical
(GC)30
DNA duplex single molecule
experimental
curr
ent
(nA
)Voltage (V)
Electron Transfer Rate vs. Conduction
Established correspondence (in formulation)
ET rate constant Electric conductance
Chemical yield Electric current
Donor/Acceptor Electrodes
(chem. potential) DA eV (applied voltage)
See reviews, Nitzan, Ann. Rev. Phys. Chem. 52 (2001) 681;
Yan & Zhang, J. Theo. & Comput. Chem. 1 (2002) 225
(J.K.Barton; B.Giese; G.B.Schuster; P.F.Babara)
G•+ATCTTGAGTGGGC TAGAACTCACCC
donoracceptor
Hole chargetrapper
Experimental Observations
Side reactions: deprotonation of G+
w/ surrounding H2O
G G… G Acceptor1 2 n
knk1 kn-1
G Acceptorkn kjkj-1k1
1 j-
1
j n
IjIj-1 InI1I0
J1 Jj-1 Jj Jn
G G… G Acceptor1 2 n
knk1 kn-1
The Ohm’s Law: Exact ResultsYan/Li/Zhang, JCP (01) 114:8248
ET rate constant Electric conductance
Chemical yield Electric current
Effect of Finite Incoherence:Partially Coherent Tunneling
via Büttiker’s scattering matrix (Phenomenological model)