Focus on Interference in Mesoscopic Systems

Abstract

The technological advances of the last few decades have created the possibility to build very small electronic devices, on the nanometric scale. The technological potential of such devices are broad, including, for example, quantum information processing, spintronics and molecular circuits. This opened the new field of nanotechnology.On such small scales, the physics of these devices is dominated by quantum mechanics: the electrons are described by wave functions, and the controllable information involves the much larger Hilbert space of these wave functions. The major feature of wave functions is their interference: complex wave functions have both a magnitude and a phase, and many quantum effects involve these phases. This led to the creation of the new field of mesoscopic physics. In this field, both experimental and theoretical efforts are being invested into the understanding of simple small scale systems, such as quantum dots, rings, low dimensional conducting channels, point contacts and more. In some sense one is now able to build and study artificial atoms and molecules, and control their interaction parameters. For sufficiently simple geometries there has been significant progress in the understanding of the physical properties, however many issues remain open, requiring further research.This focus issue of New Journal of Physics covers a selection of topics involving current research on quantum interference phenomena in mesoscopic systems. Specific systems include single and double quantum dots, and especially the ring geometry used for interferometry. Particular physics issues include decoherence and dephasing, the Fano effect, current–voltage correlations and noise, interactions with phonons and non-equilibrium transport, electron–electron interactions and the Kondo effect. Several papers discuss the Aharonov–Bohm interferometer (which was one of our main motivations in initiating this issue). In particular, these papers address the phases measured in such a device, and in particular the issues of phase lapses and level occupation switching.Many of the issues listed above are not fully settled. We hope that this collection demonstrates the progress already achieved, and sets the ground for further investigations into these issues.The articles below represent the first contributions and further additions will appear.Focus on Interference in Mesoscopic Systems ContentsTransport properties of multiple quantum dots arranged in parallel: results from the Bethe ansatz Robert M KonikLevel-occupation switching of the quantum dot, and phase anomalies in mesoscopic interferometry P G Silvestrov and Y ImryKondo resonance enhanced supercurrent in single wall carbon nanotube Josephson junctions K Grove-Rasmussen, H Ingerslev Jørgensen and P E LindelofPhase lapses in transmission through interacting two-level quantum dots C Karrasch, T Hecht, A Weichselbaum, J von Delft, Y Oreg and V Meden Universal phase lapses in a noninteracting model Yuval Oreg Entanglement, measurement, and conditional evolution of the Kondo singlet interacting with a mesoscopic detector Kicheon Kang and Gyong Luck Khym Transmission phase lapses in quantum dots: the role of dot–lead coupling asymmetry D I Golosov and Yuval Gefen Nonequilibrium transport through coupled quantum dots with electron–phonon interaction Akiko Ueda and Mikio Eto Interference effects in interacting quantum dots Moshe Goldstein and Richard Berkovits Current–voltage correlations in interferometers Heidi Förster, Peter Samuelsson and Markus Büttiker Charge imbalance, crossed Andreev reflection and elastic co-tunnelling in ferromagnet/superconductor/normal-metal structures P Cadden-Zimansky, Z Jiang and V Chandrasekhar Kondo effect in asymmetric Josephson couplings through a quantum dot Yoshihide Tanaka, Akira Oguri and A C Hewson Interference effects in an Aharonov–Bohm ring with random quantum dots Tomosuke Aono and Kazutaka Takahashi Interference through quantum dots Y Tokura, H Nakano and T Kubo Coherence oscillations in dephasing by non-Gaussian shot noise Izhar Neder and Florian Marquardt Interference in a quantum dot molecule embedded in a ring interferometer Thomas Ihn, Martin Sigrist, Klaus Ensslin, Werner Wegscheider and Matthias Reinwald Amnon Aharony, Ben Gurion University, Beer Sheva, Israel Shingo Katsumoto, University of Tokyo, Japan