Transport through Andreev bound states in a graphene quantum dot

Dirks, Travis; Hughes, Taylor L.; Lal, Siddhartha; Uchoa, Bruno; Chen, Yung-Fu; Chialvo, Cesar; Goldbart, Paul M.; Mason, Nadya
May 2011
Nature Physics;May2011, Vol. 7 Issue 5, p386
Academic Journal
When a low-energy electron is incident on an interface between a metal and superconductor, it causes the injection of a Cooper pair into the superconductor and the generation of a hole that reflects back into the metal-a process known as Andreev reflection. In confined geometries, this process can give rise to discrete Andreev bound states (ABS), which can enable transport of supercurrents through non-superconducting materials and have recently been proposed as a means of realizing solid-state qubits. Here, we report transport measurements of sharp, gate-tunable ABS formed in a superconductor-quantum dot (QD)-normal system realized on an exfoliated graphene sheet. The QD is formed in graphene beneath a superconducting contact as a result of a work-function mismatch. Individual ABS form when the discrete QD levels are proximity-coupled to the superconducting contact. Owing to the low density of states of graphene and the sensitivity of the QD levels to an applied gate voltage, the ABS spectra are narrow and can be continuously tuned down to zero energy by the gate voltage.


Related Articles

  • Energy transfer of highly vibrationally excited naphthalene. I. Translational collision energy dependence. Chen-Lin Liu; Hsu Chen Hsu; Yuan Chin Hsu; Chi-Kung Ni // Journal of Chemical Physics;9/14/2007, Vol. 127 Issue 10, p104311 

    Energy transfer between highly vibrationally excited naphthalene and Kr atom in a series of translational collision energies (108–847 cm-1) was studied separately using a crossed-beam apparatus along with time-sliced velocity map ion imaging techniques. Highly vibrationally excited...

  • Magnetoconcentration effect in intrinsic graphene ribbons. Sokolov, V. N.; Kochelap, V. A.; Kim, K. W. // Applied Physics Letters;9/13/2010, Vol. 97 Issue 11, p112112 

    We consider transverse redistributions of the electrons and holes in intrinsic graphene ribbons under the influence of crossed electric and magnetic fields, i.e., the magnetoconcentration effect. The electron and hole transport is described from the Boltzmann kinetic equation assuming the local...

  • Edge dopant energy levels of graphene nanoribbons. Yang Lu; Jing Guo // Applied Physics Letters;9/13/2010, Vol. 97 Issue 11, p113102 

    Edge doping of graphene flakes and graphene nanoribbons (GNRs) was achieved in recent experiments. Atomistic self-consistent simulations are performed in this study to compute the edge dopant energy levels of GNRs. The results indicate that the energy required to ionize the edge dopant in a...

  • Characterization of triplet-triplet annihilation in organic light-emitting diodes based on anthracene derivatives. Kondakov, D. Y. // Journal of Applied Physics;Dec2007, Vol. 102 Issue 11, p114504 

    We report that the steady-state electroluminescence in organic light-emitting diodes (OLEDs) based on anthracene derivatives has a substantial contribution from annihilation of triplet states generated by recombining charge carriers. For the OLED devices of the following general structure:...

  • Electrocaloric effect on graphenes. Reis, M. S.; Soriano, S. // Applied Physics Letters;3/18/2013, Vol. 102 Issue 11, p112903 

    The present Letter explores the electrocaloric effect of graphene nano-ribbons, with a longitudinal electric field and transversal magnetic field. Special features of the effect can be ruled and tuned by the applied fields as, for instance, the unusual inverse effect, created by the Landau...

  • Electric field driven magnetic phase transition in graphene nanoflakes. Zhou, Aiping; Sheng, Weidong; Xu, S. J. // Applied Physics Letters;9/23/2013, Vol. 103 Issue 13, p133103 

    Within the framework of Hubbard model, a bowtie-shaped graphene nanoflake is identified to undergo an electric-field induced phase transition from an antiferromagnetic ground state. Unlike the case of half-metallic graphene nanoribbons, the electric field here leads to a non-magnetic state...

  • Energy transfer of highly vibrationally excited naphthalene. II. Vibrational energy dependence and isotope and mass effects. Chen-Lin Liu; Hsu Chen Hsu; Yuan Chin Hsu; Chi-Kung Ni // Journal of Chemical Physics;3/28/2008, Vol. 128 Issue 12, p124320 

    The vibrational energy dependence, H and D atom isotope effects, and the mass effects in the energy transfer between rare gas atoms and highly vibrationally excited naphthalene in the triplet state were investigated using crossed-beam/time-sliced velocity-map ion imaging at various translational...

  • Chemistry revealed. Georgescu, Iulia // Nature Physics;Jul2013, Vol. 9 Issue 7, p388 

    The article discusses a study that provides a clearer picture of the complex surface chemistry, citing that cyclization processes are the keys to the bottom-up molecular gathering of polyaromatic hydrocarbons and after an unspecified period of time, of more composite graphene-like nanostructures.

  • Energy and temperature dependence of electron effective masses in silicon. Cavassilas, Nicolas; Autran, Jean-Luc; Aniel, Fre´de´ric; Fishman, Guy // Journal of Applied Physics;8/1/2002, Vol. 92 Issue 3, p1431 

    A k·p model is used to theoretically investigate the energy and lattice temperature dependence of both transverse and longitudinal "curvature" electron effective masses in silicon. The temperature dependence of the carrier concentration conduction effective masses in the range of 10-550 K is...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics