Report on the workshop Quantum noise and measurement in engineered electronic systems - QNM12
at the Max Planck Institute for the Physics of Complex Systems Dresden (Germany)
October 8 - 12, 2012

Scientific Organizers:
Wolfgang Belzig1, Yuli V. Nazarov2, Michel Devoret3
1 Department of Physics, University of Konstanz, Konstanz, Germany
2 Kavli Institue of Nanoscience, TU Delft, Delft, The Netherlands
3 Department of Applied Physics, Yale University, New Haven, USA

The aim to manipulate, control, and measure nanoelectronic devices deep in the quantum regime has shaped the last decade in mesoscopic physics. Much of the fundamental interest in nanoscopic and microelectronic quantum circuits stems from the fact that environmental effects and the measurement procedure itself have to be considered quantum mechanically, which poses a challenge to experimentalists as well as theorists. Understanding the interplay between quantum fluctuations and amplifcation at the quantum limit requires a more detailed understanding of complex quantum electronic circuits. A similar fundamental motivation comes from the enterprise to experimentally and theoretically investigate higher-order correlations functions or, more generally, the full counting statistics of electrons passing in a nanodevice.

The workshop QNM gathered 70 scientists from 22 countries to discuss the current state of the fields of quantum manipulation and electronic quantum shot noise in experiment and theory. In the field of quantum electronic shot noise the focus was on new aspects of time-resolved correlations in electronic currents (Büttiker, Levitov, Glattli, Reulet) and the detection of unusual statistical many-body properties manifesting themselves in scattered current correlations (von Ruitenbeek, Heiblum, Schönenberger, Martin, Deblock, König, Pothier). The quantum manipulation of superconducting transmon qubits has progressed tremendously, leading extremely long coherence time and long-distance entanglement, paving the way to realistically explore the possibilities of quantum feedback (Schoelkopf, Wallraff, DiCarlo, Siddiqi, Brandes). The fundamentals of quantum thermodynamics can nowadays be detected with single-event resolution allowing to test uctuations relations in a novel regime (Schön, Pekkola, Hänggi). The intimate connection of quantum measurement processes with quantum bits, quantum noise and nano mechanics is underscoring a common theme of the whole workshop (Molmer, Gefen, Clerk). Manipulating mechanical systems in the quantum regime using optical fields or forces has recently became a major topic in nanomechanics (Kippenberg, von Oppen, Marquardt). A rather new development is the cross coupling of circuit quantum electrodynamics with quantum dots (Ensslin, Kontos). These talks by the invited speakers were complemented by 8 shorter contributions. Note that about a third of the talks were given by younger researchers and caused a wind of change to the field of quantum noise and manipulation. During the two poster session lively discussion continued until late at night and many participants used the whole week to explain their posters to other experts in the field. Finally, the broader scope of quantum measurement with an emphasis on electronic circuits was presented by S. Girvin (Yale) to the public in the framework of the weekly colloquium.

As a result of the workshop different aspects of quantum noise in electronic circuits have brought together the communities of circuit QED, quantum shot noise, full counting statistics and nanomechnics. In future we expect a fruitful interaction to achieve challenging goals like quantum feedback, high-frequency quantum standards and investigations of the full statistics of complex electron-phonon-photon systems deep in the quantum regime.