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Quantum Coherence in Nanoscale Systems

English title Quantum Coherence in Nanoscale Systems
Applicant Zumbühl Dominik
Number 138217
Funding scheme Project funding (Div. I-III)
Research institution Departement Physik Universität Basel
Institution of higher education University of Basel - BS
Main discipline Condensed Matter Physics
Start/End 01.10.2011 - 30.09.2014
Approved amount 600'000.00
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Lay Summary (English)

Lead
Lay summary

Quantum coherence in nanoscale systems enables study of fundamental physics in condensed matter systems and has promising applications for quantum information processing. Experimental realization of proposed qubits in the solid state and investigation of the underlying physics controlling coherence is at the forefront of modern condensed matter physics. In this project, we perform electronic measurements on semiconductor nanostructures such as 1D quantum wires, spin qubits in quantum dots and 2D electron gases in order to study electron spins and nuclear spins as well as their interactions.

Experiments will investigate quantum transport through semiconductor nanostructures which will be fabricated in-house with both optical- and electron beam lithography nanofabrication techniques using GaAs high-mobility 2D electron gas materials, grown in molecular beam epitaxy labs. Experiments are typically performed in dilution refrigerators at millikelvin temperatures in magnetic fields. Measurements are done using electronic low-noise techniques and may involve nanosecond-pulsing and microsecond readout schemes.

We are affiliated with the NCCR Nanoscale Science center (www.nccr-nano.org) and the NCCR Quantum Science and Technology (http://www.nccr-qsit.ethz.ch/) of the Swiss NSF, the Basel Center for Quantum Computing and Quantum Coherence (www.qc2.unibas.ch) and the NSEC Harvard Nanoscale Science and Engineering Center (www.nsec.harvard.edu) of the US National Science Foundation.

For more information, visit http://ZumbuhlLab.unibas.ch.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Intrinsic Metastabilities in the Charge Configuration of a Double Quantum Dot
Biesinger Daniel, Scheller Christian, Braunecker Bernd, Zimmerman Jeramy, Gossard Arthur, Zumbuhl Dominik (2015), Intrinsic Metastabilities in the Charge Configuration of a Double Quantum Dot, in Physical Review Letters, 115, 106804.
Tunnel-Junction Thermometry Down to Millikelvin Temperatures
Feshchenko A. V., Casparis L., Khaymovich I. M., Maradan D., Saira O.-P., Palma M., Meschke M., Pekola J. P., Zumbühl D. M. (2015), Tunnel-Junction Thermometry Down to Millikelvin Temperatures, in Phys. Rev. Applied, 4, 034001-034001.
GaAs Quantum Dot Thermometry Using Direct Transport and Charge Sensing
Maradan D., Casparis L., Liu T.-M., Biesinger D. E. F., Scheller C. P., Zumbühl D. M., Zimmerman J. D., Gossard A. C. (2014), GaAs Quantum Dot Thermometry Using Direct Transport and Charge Sensing, in Journal of Low Temperature Physics, 175, 784.
Hybrid Quantum Dot-2D Electron Gas Devices for Coherent Optoelectronics
Dettwiler F., Fallahi P., Scholz D., Reiger E., Schuh D., Badolato A., Wegscheider W., Zumbühl D. M. (2014), Hybrid Quantum Dot-2D Electron Gas Devices for Coherent Optoelectronics, in arxiv, 1403, 7775.
Possible Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires
C. P. Scheller, T.-M. Liu, G. Barak, A. Yacoby, L. N. Pfeiffer, K. W. West, D. M. Zumbuhl (2014), Possible Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires, in Phys. Rev. Lett., 112, 066801.
Silver-Epoxy Microwave Filters and Thermalizers for Millikelvin Experiments
Scheller C. P., Heizmann S., Bedner K., Giss D., Meschke M., Zumbühl D. M., Zimmerman J. D., Gossard A. C. (2014), Silver-Epoxy Microwave Filters and Thermalizers for Millikelvin Experiments, in Applied Physics Letters, 104, 211106.
Spontaneous Helical Order of Electron and Nuclear Spins in a Luttinger Liquid
Scheller C. P., Braunecker B., Loss D., Zumbühl D. (2014), Spontaneous Helical Order of Electron and Nuclear Spins in a Luttinger Liquid, in SPS Progress in Physics, 44, 23-28.
Evidence for Disorder Induced Delocalization in Graphite
L. Casparis, D. Hug, D. Kölbl, D. M. Zumbuhl (2013), Evidence for Disorder Induced Delocalization in Graphite, in arXiv (under review), 1301, 2727.
Transport spectroscopy of disordered graphene quantum dots etched into a single graphene flake
D. Kölbl, D. M. Zumbühl (2013), Transport spectroscopy of disordered graphene quantum dots etched into a single graphene flake, in arXiv, 1307, 8163.
Breakdown of the Korringa Law of Nuclear Spin Relaxation in Metallic GaAs
Koelbl D, Zumbuhl DM, Fuhrer A, Salis G, Alvarado SF (2012), Breakdown of the Korringa Law of Nuclear Spin Relaxation in Metallic GaAs, in Phys. Rev. Lett., 109, 086601-4.
Metallic Coulomb Blockade Thermometry down to 10 mK and below
Casparis L, Meschke M, Maradan D, Clark AC, Scheller C, Schwarzwaelder KK, Pekola JP, Zumbuhl DM (2012), Metallic Coulomb Blockade Thermometry down to 10 mK and below, in Rev. Sci. Instr., 83, 083903-4.

Collaboration

Group / person Country
Types of collaboration
Prof. D. Awschalom, University of Chicago United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Dr. Art Gossard, University of California, Santa Barbara United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
NSEC Network, based at Harvard University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
Prof. Dr. Christian Schönenberger Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Prof. Dr. Daniel Loss Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Prof. Amir Yacoby, Harvard University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. J. C. Egues, University of Sau Paulo Brazil (South America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Prof. W. Wegscheider, ETH Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Dr. Loren Pfeiffer, Princeton University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Condensed matter physics seminar, Princeton University Individual talk Edge State Spectroscopy with a GaAs Quantum Wire 14.11.2016 Princeton, New Jersey, United States of America Zumbühl Dominik;
Condensed matter physics seminar, Harvard University Individual talk Edge State Spectroscopy with a GaAs Quantum Wire 10.11.2016 Cambridge, MA, United States of America Zumbühl Dominik;
International Conference on Physics and Applications of Spin-Related Phenomena in Solids PASPS-9, Kobe, Japan Talk given at a conference Direct determination of spin-orbit parameters from quantum transport measurements 08.08.2016 Kobe, Japan Weigele Pirmin Jonas;
NCCR QSIT student school and annual meeting 2016, Arosa, Switzerland Poster Spin relaxation anisotropy and spin-orbit coupling in a single electron GaAs quantum dot01.02. 01.02.2016 Arosa, Switzerland Weigele Pirmin Jonas;
Invited speaker, seminar at RIKEN national research laboratories Individual talk Breaking the mK-Barrier in Nanoelectronics 26.10.2015 Wako Saitama, Tokyo, Japan, Japan Zumbühl Dominik;
Invited speaker, seminar at NTT basic research laboratories Individual talk Breaking the mK-Barrier in Nanoelectronics 22.10.2015 Atsugi, Japan, Japan Zumbühl Dominik;
Quantum Nanostructures and Electron-Nuclear Spin Interactions, Spintronics conference Talk given at a conference Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires 19.10.2015 Tohoku Formu for Creativity, Sendai, Japan, Japan Zumbühl Dominik;
Spintech VIII" 8th international school and conference on Spintronics and Quantum Information Talk given at a conference Spin Relaxation in GaAs Spin Qubits 11.08.2015 Basel, Switzerland Zumbühl Dominik;
European microkelvin platform workshop Talk given at a conference Breaking the mK-Barrier in Nanoelectronics 26.05.2015 Heidelberg, Germany, Germany Zumbühl Dominik;
"Concepts in Spintronics" follow-on workshop, Kavli Institute for Theoretical Physics Talk given at a conference Electrical spin protection and manipulation via gate-locked spin-orbit fields 25.02.2015 University of California, Santa Barbara, United States of America Zumbühl Dominik;
Invited seminar speaker, Joint Quantum Institutes, University of Maryland, College Park Individual talk Spin Helices in GaAs Quantum Wells and Wires 23.02.2015 College Park, MD, United States of America Zumbühl Dominik;
NCCR Quantum Science and Technology, 4th site visit Poster Helical States and Spin Helices in Low-Dimensional Systems, Lucas Casparis and Taras Patlatiuk 06.11.2014 Zurich, Switzerland Zumbühl Dominik;
SNI annual meeting, Lenzerheide Talk given at a conference Cooling electronic nanodevices to ultralow temperature on a cryogen-free dilution refrigerator, Mario Palma 11.09.2014 Lenzerheide, CH, Switzerland Zumbühl Dominik;
International conference on Low Temperature Physics LT27, Buenos Aires, Argentina Talk given at a conference "Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires", Christian Scheller, and 3 posters by M. Lafkioti and M. Palma 06.08.2014 Buenos Aires, Argentina, Argentina Zumbühl Dominik;
International conference on Physics and Applications of Spin related Phenomena in Solids PASPS VIII, Washington DC Talk given at a conference Electrical Spin Protection and Manipulation via gate-locked spin-orbit fields, Dominik Zumbuhl 28.07.2014 Washington DC, United States of America Zumbühl Dominik;
NCCR QSIT Junior Meeting 2014, Pasugg, Switzerland Talk given at a conference Spin Tunneling and Spin Relaxation in GaAs Quantum Dots ", Leon Camenzind. 10.06.2014 Passugg, CH, Switzerland Zumbühl Dominik;
Swiss Nanoconvention 2014, Brugg, Switzerland Talk given at a conference Controlling Spins in Semiconductor Nanostructures, Dominik Zumbuhl 21.05.2014 Brugg, AG, Switzerland Zumbühl Dominik;
NCCR QSIT student school and annual meeting 2014, Arosa, Switzerland Talk given at a conference "Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires", Christian Scheller, and 2 posters by 3 group members 03.02.2014 Arosa, Switzerland Maradan Dario; Zumbühl Dominik;
Swiss Nanoscience Institute SNI Winterschool "Nano in the Snow" Talk given at a conference Nuclear refrigeration for cooling nanoelectronic devices on a cryogen-free dilution refrigerator, Mario Palma 29.01.2014 Kandersteg, Switzerland Zumbühl Dominik;
Concepts in Spintronics, Kavli Institute for Theoretical Physics, University of California, Santa Barbara Talk given at a conference Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires 30.09.2013 Santa Barbara, United States of America Zumbühl Dominik;
International Workshop: Topology and Nonequilibrium in Low-Dimensional Electronic Systems, Max Planck Institut, Dresden, Germany Talk given at a conference Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires 16.09.2013 Dresden, Germany Zumbühl Dominik;
Microkelvin workshop, Sannas, Helsinki, Finland Talk given at a conference Towards Microkelvin Quantum Transport Experiments in Nanosamples 08.09.2013 Sannas, Finland Maradan Dario; Zumbühl Dominik;
Cryocourse 2013 Summer School, Grenoble, France Poster attended by Mario Palma and Pirmin Weigele 25.08.2013 Grenoble, France Zumbühl Dominik;
2nd NCCR QSIT Student School and 3rd NCCR QSIT General Meeting, school presentation Talk given at a conference Semiconductor Spins in quantum transport experiments 28.01.2013 Arosa, Switzerland Maradan Dario; Zumbühl Dominik; Biesinger Daniel; Weigele Pirmin Jonas;
Conference of the EPS Condensed Matter Division, Edinburgh, UK Talk given at a conference Evidence for Nuclear Spin Order in GaAs Quantum Wires at Ultra-Low Temperatures 03.09.2012 Edinburgh, Great Britain and Northern Ireland Zumbühl Dominik;
Condensed matter seminar, University of Groningen, Netherlands Individual talk Intrinsic Charge Fluctuations and Nuclear Spin Order in GaAs Nanostructures, Dominik Zumbuhl 12.07.2012 Groningen, Netherlands Zumbühl Dominik;
International summer school and conference "Scuola Enrico Fermi", Varenna, Italy Talk given at a conference Intrinsic Charge Fluctuations and Nuclear Spin Order in GaAs Nanostructures, Dominik Zumbuhl 19.06.2012 Varenna, IT, Italy Biesinger Daniel; Zumbühl Dominik;
European Microkelvin Meeting, Smolenice, Slovakia Talk given at a conference Evidence for Helical Nuclear Order in GaAs Quantum Wires, Dominik Zumbuhl, Mario Palma, Lucas Casparis 01.03.2012 Smolenice, Slovakia Maradan Dario; Zumbühl Dominik;
Physics colloquium, Trintiy college, Ireland Individual talk Towards Microkelvin Temperatures in Nanosamples, Dominik Zumbuhl 17.01.2012 Dublin, Ireland Zumbühl Dominik;


Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions Quanten und Nanowelten, Gelterkinden, Switzerland, Ultimative Experimente fur den Quantencomputer German-speaking Switzerland 2016
Talks/events/exhibitions TecDay Bündner Kantonsschule, Chur, Modul: \Der Quantencomputer - Superrechner der Zukunft?" German-speaking Switzerland 2016
Talks/events/exhibitions TecNight Kantonsschule Wohlen, Modul: \Der Quantencomputer - Superrechner der Zukunft?" German-speaking Switzerland 2016
Talks/events/exhibitions Saturday Morning Physics, Der Quantencomputer – Superrechner der Zukunft? German-speaking Switzerland 2015
Talks/events/exhibitions TecDay Gymnasium Kirschgarten, Basel, Modul: \Der Quantencomputer - Superrechner der Zukunft?" German-speaking Switzerland 2015
Talks/events/exhibitions TecDay Gymnasium Thun Schadau, Modul: \Der Quantencomputer - Superrechner der Zukunft?" German-speaking Switzerland 2015
Media relations: radio, television Horizon 2020 funding, Feb 2014 SRF1 Tagesschau 17.2.2014 German-speaking Switzerland 2014
Media relations: radio, television SNI Youtube video video "Exploring the Nanoworld at the Swiss Nanoscience Institute" youtube Western Switzerland International German-speaking Switzerland Rhaeto-Romanic Switzerland Italian-speaking Switzerland 2014
Talks/events/exhibitions TecDay Gym Lerbermatt, Koeniz, "Der Quantumcomputer: Supercomputer der Zukunft" German-speaking Switzerland Western Switzerland 2014
Talks/events/exhibitions Besuch Grossratspräsident Stadt Basel German-speaking Switzerland 2013

Awards

Title Year
Teaching award "Goldene Kreide", Physics Department, Basel University 3rd highest student-rating of the mandatory lectures in the Department Introduction to condensed matter physics 2015
Camille-and Henry Dreyfus fellowship of the University of Basel for Lucas Casparis for excellent work on ongoing Ph. D. thesis 2014
Faculty of Science prize, University of Basel for Christian Scheller, PhD. student in the Zumbuhl group Best Ph. D. thesis of the Faculty of Science, University of Basel, 2013/2014 (experimental discovery of the nuclear helimagnet) 2014
QSTARTER award of the NCCR quantum science and technology 1st prize, Christian Scheller, for cryogenic microwave filters and thermalizers 2014
Teaching award "Goldene Kreide", Physics Department, Basel University highest student-rating of the mandatory lectures in the Physics Department Introduction to condensed matter physics 2014

Associated projects

Number Title Start Funding scheme
157213 Quantum Coherence in Nanoscale Systems 01.10.2014 Project funding (Div. I-III)
121905 Quantum Coherence in Nanoscale Systems 01.10.2008 Project funding (Div. I-III)
121905 Quantum Coherence in Nanoscale Systems 01.10.2008 Project funding (Div. I-III)

Abstract

Macroscopic control of coherent quantum states is a major theme in much of modern physics because quantum coherence enables study of fundamental physics and has promising applications for quantum information processing. The potential significance of quantum computing is now widely recognized, in the physics community and beyond. Thisproposal consists of three projects: nuclear spin magnetism in GaAs quantum wires, spin-orbit coupling and the persistent spin helix in GaAs 2D electron gases and single electron spin relaxation physics.The coherence in electron spin qubits is known to be limited by the fluctuations of the nuclear spin ensemble. These fluctuations can be fully suppressed and coherence strongly enhanced if the nuclear spin system is in a ferromagnetically ordered state. As recently proposed by theorists, a correlated state of matter with full nuclear order is induced by an effective RKKY interaction mediated by the interacting 2D electron gas, with rich newphysics worth studying in its own right. In 1D systems, due to very strong electron-electron interactions, the ordering temperature is an experimentally easily accessible range, around Tc = 80 mK for nuclear order in 1D GaAs cleaved edge overgrowth quantum wires (project A) at external B=0. The nuclear order is manifestly visible in quantum transport through a suppression of the wire conductance from 2e2/h down to 1e2/h at low temperatures T<
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