Kondo effect

Park J, Pasupathy AN, Goldsmith JI, Chang C, Yaish Y, Petta JR, Rinkoski M, Sethna JP, Abruna HD, McEuen PL, Ralph DC (2002) Coulomb blockade and the Kondo effect in single-atom transistors. Nature 417(6890) 722-725... 

In a heavy fermion compound Yb MnSbn, the dephasing rate of the coherent optical phonons decreased with lowering temperature above Curie temperature Tc, but increased below Tc- The results were attributed to the coupling between an optical phonon mode and the Kondo effect [100]. 

Cgo single molecules between electrodes fabricated by electromigration [103] to create single Cgo molecule transistors were measured at a temperature of 40 mK. The results showed the coexistence and competition of the effects of Coulomb repulsion, Kondo correlations and superconductivity [104]. The Kondo effect had been previously observed in similar devices [105]. Recently a SAM of a tricarboxylic acid fullerene derivative was used to fabricate a transistor. The SAM was created by allowing the fullerene compound to self assemble on top of an AI2O3 layer just above the aluminum drain electrode the source lead was created by... 

Roch N, Winkehnann CB, Florens S et al (2008) Kondo effect in a Cgo single-molecule transistor. Phys Status Solid B 245 1994—1997... 

An P, Bialczak RC, Martinek J, Grose JE, Donev LAK, McEuen PL, Ralph DC (2004) The Kondo effect in the presence of ferromagnetism. Science 306 86-89... 

We use this formula in Chapter 3 in a discussion of the Kondo effect. 

Formulae similar to (6) have wide application to the movement of a system through an activated intermediate state, and will be applied to a simplified description of the Kondo effect in Chapter 3. For polarons the effect is to allow band motion at low temperatures with well-defined wavenumber k but enhanced effective mass mp given by... 

For a discussion of the energy loss in such a situation see Austin and Mott (1969a, b) and Bosman and van Daal (1970) for the analogous situation of a magnetic moment in systems such as CnMn showing a Kondo effect, see Chapter 3, Section 8. 

The model of a degenerate gas of spin polarons suggests that if the direct or RKKY interaction between moments is weak and EF too great to allow ferromagnetism then the moments might all resonate between their various orientations. This would mean that it is possible in principle to have a heavily doped magnetic semiconductor or rare-earth metal in which there is no magnetic order, even at absolute zero. This possibility is discussed further in Section 8 in connection with the Kondo effect. 

Many papers have been published on the theory of die Kondo effect, including some exact solutions. We recommend the 260 page review by Tsvelich and Weigmann (1983). Our aim in giving a simple non-mathematical account is to point out the similarity between the enhancement of the effective mass that occurs in crystalline metallic systems near to the conditions for a Mott transition (Chapter 4), and also to address the possible effects of free spins in doped semiconductors near the transition (Chapter 5). 

The question of the existence of the Kondo effect in amorphous systems is of interest for the considerations of Chapter 5. There is no theoretical reason to suppose that the Kondo temperature will be greatly affected on the other hand, the short mean free path l should cut down the RKKY interaction, which, for distances r greater than / should fall off as e-r/ (de Gennes 1962). In alloys... 

Two-Channel Kondo Effect in a Modified Single Electron Transistor... 

Enormous progress has been achieved in the experimental realization of such nano-devices, we only mention the development of controllable single-molecule junctions [8]-[22] and scanning tunneling microscopy based techniques [23]— [44]. With their help, a plethora of interesting phenomena like rectification [18], negative differential conductance [9,35], Coulomb blockade [10,11,15,16,21, 23], Kondo effect [11,12], vibrational effects [10,13,14,16,21,25,31-33,35,36], and nanoscale memory effects [34,39,40,42,44], among others, have been demonstrated. 

During last years many new methods were developed to describe transport at finite voltage, with focus on correlation and inelastic effects, in particular in the cases when Coulomb blockade, Kondo effect and vibronic effects take place. 

In the case of a single site junction with two (spin-up and spin-down) states and Coulomb interaction between these states (Anderson impurity model), the linear conductance properties have been successfully studied by means of the EOM approach in the cases related to Coulomb blockade [203, 204] and the Kondo effect [205]. Later the same method was applied to some two-site models [206-209], Multi-level systems were started to be considered only recently [210,211], Besides, there are some difficulties in building the lesser GF in the nonequilibrium case (at finite bias voltages) by means of the EOM method [212-214],... 

Finally, we want to mention briefly three important fields of research, that we do not consider in the present review the theory of Kondo effect [205,228-234], spin-dependent transport [235-239], and time-dependent transport [83, 240-243],... 

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