Exploiting the rich design space of organic molecules for applications in future electronic devices is one of the main challenges in nanotechnology. Several groups have recently demonstrated, for a limited set of molecules, clear single-molecule characteristics and fair agreement with computations. Now that attaching leads to individual molecules has been demonstrated we naturally enter into the next exciting phase of the research, where molecule-specific properties can be engineered and studied. The most prominent property that distinguishes organic molecules from inorganic quantum dots and nanowires is that they are floppy nano-objects with a strong coupling between charge transport and vibrational degrees of freedom (vibrons). This coupling is predicted to influence transport in dramatic ways as it may destroy the coherence of charge carriers on the molecules and can lead to strong nonequilibrium effects. Many exciting predictions have been discussed in the recent literature showing unique features of single-molecule junctions. These properties can be designed and controlled by chemists.
Figure 1: Magneto-mechanical excitation spectrum of the SMM with S = 3/2. Magnetic states, lying on an invert...
Figure 2:
Logarithmic color plot of the SMM differential conductance G(V) normalized to the value and for T ...
Figure 3: Effect of the spin–vibration coupling on the QST-Kondo peak: SMM differential conductance shown for...
Figure 4: QST-Kondo temperature TK in units of bandwidth 2W (log color scale) determined from the NRG level f...
Figure 5: Magnetic field evolution of the differential conductance normalized to G0 (log color scale) for the...
Figure 1: Molecular structures of AC, AQ, and AH.
Figure 2: (A) Schematics of the system configuration and (B) pictures of the mechanical part in the MCBJ setu...
Figure 3: Conductance and voltage output for the piezo stack versus time for 0.1 mM AC in THF/decane (v:v = 1...
Figure 4: Individual conductance–distance traces and histogram constructed from these sets of three traces fo...
Figure 5: (A–C) Individual current–voltage curves of (A) a gold–gold contact, (B) a gold|AC|gold molecular ju...
Figure 6: (A) 2-D I–V histogram constructed from 2500 individual traces recorded during a current–distance st...
Figure 7: Conductance histograms of 0.1 mM AC in THF/decane (v:v = 1:4). Black: From 500 current–distance str...
Figure 8: 1-D conductance histograms and conductance–distance 2-D histograms constructed from 500 individual ...
Figure 9: Plateau-length distributions (black) and Gaussian fits (red) of (A) AC (B) AQ (C) AH and (D) the bl...
Figure 10: Model of the breaking process of the Au|AC|Au junction. (A) A typical trace with labels indicating ...
Figure 1: Structural formula of ZnTPPdT–Pyr (b) Top: Setup of the mechanically controllable break-junction (M...
Figure 2: Trace histograms constructed from 500 consecutive breaking traces taken at room temperature and 100...
Figure 3: Low-temperature I(V) characteristics of junctions exposed to (a) DCM and (b) ZnTPPdT–Pyr. The DCM s...
Figure 1: Conductance histogram of electrochemically deposited atomic-scale silver contacts giving evidence f...
Figure 2: Number of conductance levels with level length greater than Δt as a function of Δt. The plot is giv...
Figure 3: Conductance histogram for electrochemically deposited atomic-scale silver contacts giving evidence ...
Figure 4: (G/G0)1/2 at the positions of the maxima observed in Figure 3 versus their sequentially numbered index. We ...
Figure 5: Illustration of a nanowire with fcc crystal structure and hexagonal cross-sectional area for two di...
Figure 1: (a) Supercell used to model the gold/alkanediamine junctions. Similar supercells were used for n = ...
Figure 2: (a) Isosurfaces for the HOMO and HOMO−2 orbitals of the C6-alkanediamine molecule. (b) HOMO and HOM...
Figure 3: Change in the correlation energy of the HOMO and HOMO–2 energy levels when the molecules are taken ...
Figure 4: The molecular valence-band edge (or HOMO) as a function of coverage for an n = 6 alkane. The number...
Figure 5: The transmission function calculated by GW for a molecular length of n = 2, n = 4 and n = 6 at a co...
Figure 6: Calculated conductance plotted as a function of the molecular length for a coverage corresponding t...
Figure 1: Experimental setup and schematic view of the formation process of the single-molecule junction duri...
Figure 2: Typical conductance traces of Au contacts in tetraglyme (green), water (red), mesitylene (blue) con...
Figure 3: Conductance histograms of Au contacts in tetraglyme (green), water (red), mesitylene (blue) contain...
Figure 4: Typical conductance traces of Au contacts in tetraglyme (green), water (red), mesitylene (blue) con...
Figure 5: Conductance histograms of Au contacts in tetraglyme (green), water (red), and mesitylene (blue) con...
Figure 1: The system considered in the present study is a four-atom carbon chain bridging two graphene electr...
Figure 2: Current–Voltage (I−Vb) curves at different Vg.
Figure 3: (a) Motion of the two phonon modes around 200 meV. (b) Motion of the runaway mode at Vg = 0.6 V, an...
Figure 4: (a) Inverse Q-factor (1/Q) as a function of gate voltage, Vg, at Vb = 1 V for the two modes around ...
Figure 5: (a) Effective phonon number (N) for the two phonon modes around 200 meV as a function of gate volta...
Figure 6: (a) Definition of the system regions with different types of noise contributions. Leads (L,R) have ...
Figure 1: An example of a Hückel model for a four-site molecule, the numbering of the sites corresponds to th...
Figure 2: Examples of molecular structures (top) and the corresponding model systems (bottom) for true cross-...
Figure 3: The transmission through three model cross-conjugated molecules calculated using Hückel theory. In ...
Figure 4: The chemical structure (inset top), space-filling model (inset bottom) and transmission for the 2cc...
Figure 5: The local π-transmission (contributions to the transmission between pairs of atoms) for the species...
Figure 6: A modified Hückel model for 2cc with first- (solid), second- (dashed) and third- (dashed-dot) neare...
Figure 7: The chemical structure (inset top), space-filling model (inset bottom) and transmission for the 2cc...
Figure 8: The chemical structure (inset top), space-filling model (inset bottom) and transmission for the 2cc...
Figure 9: The same systems as calculated in Figure 3, but calculated by using the MDE many-body method. In both 2cc a...
Figure 1: Spectral functions A(E) = −(1/π)Tr{G(E)} at room temperature for gas-phase benzene (top panel) and ...
Figure 2: Calculated van der Waals contribution to the binding energy of benzene adsorbed on a Pt(111) surfac...
Figure 3: The trace of Γα for a Pt electrode in contact with a benzene molecule. Nine total basis states of t...
Figure 4: Eigenvalue decomposition of an ensemble of Γα matricies, showing that each lead–molecule contact ha...
Figure 5:
The distribution of charging energy (top panel) and Tr{Γ} (bottom panel) over the ensemble describ...
Figure 6: Calculated conductance histogram for the ensemble over bonding configurations and Pt surfaces. The ...
Figure 7: The calculated eigenvalue distributions for an ensemble of 1.74 × 105 (2000 bonding configurations ...
Figure 8: The calculated average total transmission averaged over 2000 bonding configurations through a Pt–be...
Figure 9: The calculated Fano factor F distribution for the full ensemble of 1.74 × 105 Pt–benzene–Pt junctio...
Figure 1:
Resonant level. The shape of the effective potential can be tuned by the bias voltage. We consider...
Figure 2: Sketch of the two-level model. Electrons tunnel through two degenerate energy levels between the le...
Figure 3: Effective potential for the mechanical motion in the two-level model. The shape of the potential ca...
Figure 4: Damping versus mechanical displacement in the two-level model. (a) Contribution γs,eq to the fricti...
Figure 5: Cartoon of the positions of the electronic levels in the dot with respect to the Fermi levels of th...
Figure 6: Dependence of the current in the two-level model on various parameters. Current as a function of me...
Figure 7: Curl of the average force and damping coefficient for the model with two vibrational modes: (a) The...
Figure 8: Limit-cycle dynamics for the model with two vibrational modes. (a) At large bias voltages, Poincaré...
Figure 9: Current–current correlation function in the presence of noise for the system with two vibrational m...
Figure 1: STM system picking up C60 with a magnetic tip, approaching a magnetic adatom on the nonmagnetic cop...
Figure 2: Transmission spectra for FM and AFM arrangements. The first row shows spin-resolved transmission sp...
Figure 3: Scattering states at E = EF of first two dominant eigenchannels for (a,b) majority and (c,d) minori...
Figure 4: Spin-resolved conductance and transmission spin polarization (TSP) vs C60-adatom separation.
Figure 5: (a) Magnetic exchange energy, (b) conductance for FM and AFM configurations (inset in log-scale) an...