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Butterworth J, Triqueneaux S, Midlik Š, Golokolenov I, Gerardin A, Gandit T, Donnier-Valentin G, Goupy J, Phuthi MK, Schmoranzer D, Collin E, Fefferman A. Superconducting aluminum heat switch with 3 nΩ equivalent resistance. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:034901. [PMID: 35364993 DOI: 10.1063/5.0079639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/26/2022] [Indexed: 06/14/2023]
Abstract
Superconducting heat switches with extremely low normal state resistances are needed for constructing continuous nuclear demagnetization refrigerators with high cooling power. Aluminum is a suitable superconductor for the heat switch because of its high Debye temperature and its commercial availability in high purity. We have constructed a high quality Al heat switch whose design is significantly different than that of previous heat switches. In order to join the Al to Cu with low contact resistance, we plasma etched the Al to remove its oxide layer and then immediately deposited Au without breaking the vacuum of the e-beam evaporator. In the normal state of the heat switch, we measured a thermal conductance of 8T W/K2, which is equivalent to an electrical resistance of 3 nΩ according to the Wiedemann-Franz law. In the superconducting state, we measured a thermal conductance that is 2 × 106 times lower than that of the normal state at 50 mK.
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Affiliation(s)
- James Butterworth
- Air Liquide Advanced Technologies, 2, rue de Clemenciere, BP 15, 38360 Sassenage, France
| | - Sébastien Triqueneaux
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
| | - Šimon Midlik
- Charles University, Ke Karlovu 3, 121 16 Prague, Czech Republic
| | - Ilya Golokolenov
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
| | - Anne Gerardin
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
| | - Thibaut Gandit
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
| | | | - Johannes Goupy
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
| | - M Keith Phuthi
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
| | | | - Eddy Collin
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
| | - Andrew Fefferman
- CNRS, Grenoble INP, Institute Neel, University Grenoble Alpes, 38000 Grenoble, France
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Yan J, Yao J, Shvarts V, Du RR, Lin X. Cryogen-free one hundred microkelvin refrigerator. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:025120. [PMID: 33648063 DOI: 10.1063/5.0036497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
A temperature below 100 µK is achieved in a customized cryogen-free dilution refrigerator with a copper-nuclear demagnetization stage. The lowest temperature of conduction electrons of the demagnetization stage is below 100 µK as measured by using a pulsed platinum nuclear magnetic resonance thermometer, and the temperature can remain below 100 µK for over 10 h. A demagnetization magnetic field of up to 9 T and a research magnetic field of up to 12 T can be controlled independently, provided by a coaxial room-temperature-bore cryogen-free magnet.
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Affiliation(s)
- Jiaojie Yan
- International Center for Quantum Materials, Peking University, Beijing 100871, China
| | - Jianing Yao
- International Center for Quantum Materials, Peking University, Beijing 100871, China
| | - Vladimir Shvarts
- Janis Research Company LLC, Wilmington, Massachusetts 01887, USA
| | - Rui-Rui Du
- International Center for Quantum Materials, Peking University, Beijing 100871, China
| | - Xi Lin
- International Center for Quantum Materials, Peking University, Beijing 100871, China
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3
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Jones AT, Scheller CP, Prance JR, Kalyoncu YB, Zumbühl DM, Haley RP. Progress in Cooling Nanoelectronic Devices to Ultra-Low Temperatures. JOURNAL OF LOW TEMPERATURE PHYSICS 2020; 201:772-802. [PMID: 33239828 PMCID: PMC7679351 DOI: 10.1007/s10909-020-02472-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/29/2020] [Indexed: 06/11/2023]
Abstract
Here we review recent progress in cooling micro-/nanoelectronic devices significantly below 10 mK. A number of groups worldwide are working to produce sub-millikelvin on-chip electron temperatures, motivated by the possibility of observing new physical effects and improving the performance of quantum technologies, sensors and metrological standards. The challenge is a longstanding one, with the lowest reported on-chip electron temperature having remained around 4 mK for more than 15 years. This is despite the fact that microkelvin temperatures have been accessible in bulk materials since the mid-twentieth century. In this review, we describe progress made in the last 5 years using new cooling techniques. Developments have been driven by improvements in the understanding of nanoscale physics, material properties and heat flow in electronic devices at ultralow temperatures and have involved collaboration between universities and institutes, physicists and engineers. We hope that this review will serve as a summary of the current state of the art and provide a roadmap for future developments. We focus on techniques that have shown, in experiment, the potential to reach sub-millikelvin electron temperatures. In particular, we focus on on-chip demagnetisation refrigeration. Multiple groups have used this technique to reach temperatures around 1 mK, with a current lowest temperature below 0.5 mK.
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Affiliation(s)
- A. T. Jones
- Department of Physics, Lancaster University, Lancaster, LA1 4YB UK
| | - C. P. Scheller
- Department of Physics, University of Basel, 4056 Basel, Switzerland
| | - J. R. Prance
- Department of Physics, Lancaster University, Lancaster, LA1 4YB UK
| | - Y. B. Kalyoncu
- Department of Physics, University of Basel, 4056 Basel, Switzerland
| | - D. M. Zumbühl
- Department of Physics, University of Basel, 4056 Basel, Switzerland
| | - R. P. Haley
- Department of Physics, Lancaster University, Lancaster, LA1 4YB UK
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Nicolí G, Märki P, Bräm BA, Röösli MP, Hennel S, Hofmann A, Reichl C, Wegscheider W, Ihn T, Ensslin K. Quantum dot thermometry at ultra-low temperature in a dilution refrigerator with a 4He immersion cell. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:113901. [PMID: 31779415 DOI: 10.1063/1.5127830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 10/26/2019] [Indexed: 06/10/2023]
Abstract
Experiments performed at a temperature of a few millikelvins require effective thermalization schemes, low-pass filtering of the measurement lines, and low-noise electronics. Here, we report on the modifications to a commercial dilution refrigerator with a base temperature of 3.5 mK that enable us to lower the electron temperature to 6.7 mK measured from the Coulomb peak width of a quantum dot gate-defined in an [Al]GaAs heteostructure. We present the design and implementation of a liquid 4He immersion cell tight against superleaks, implement an innovative wiring technology, and develop optimized transport measurement procedures.
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Affiliation(s)
- G Nicolí
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - P Märki
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - B A Bräm
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - M P Röösli
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - S Hennel
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - A Hofmann
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - C Reichl
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - W Wegscheider
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - T Ihn
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - K Ensslin
- Solid State Physics Laboratory, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
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Patlatiuk T, Scheller CP, Hill D, Tserkovnyak Y, Barak G, Yacoby A, Pfeiffer LN, West KW, Zumbühl DM. Evolution of the quantum Hall bulk spectrum into chiral edge states. Nat Commun 2018; 9:3692. [PMID: 30209251 PMCID: PMC6135798 DOI: 10.1038/s41467-018-06025-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 08/13/2018] [Indexed: 11/30/2022] Open
Abstract
One of the most intriguing and fundamental properties of topological systems is the correspondence between the conducting edge states and the gapped bulk spectrum. Here, we use a GaAs cleaved edge quantum wire to perform momentum-resolved spectroscopy of the quantum Hall edge states in a tunnel-coupled 2D electron gas. This reveals the momentum and position of the edge states with unprecedented precision and shows the evolution from very low magnetic fields all the way to high fields where depopulation occurs. We present consistent analytical and numerical models, inferring the edge states from the well-known bulk spectrum, finding excellent agreement with the experiment-thus providing direct evidence for the bulk to edge correspondence. In addition, we observe various features beyond the single-particle picture, such as Fermi level pinning, exchange-enhanced spin splitting and signatures of edge-state reconstruction.
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Affiliation(s)
- T Patlatiuk
- Departement Physik, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - C P Scheller
- Departement Physik, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland
| | - D Hill
- Department of Physics and Astronomy, University of California, Los Angeles, CA, 90095, USA
| | - Y Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, CA, 90095, USA
| | - G Barak
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - A Yacoby
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - L N Pfeiffer
- Department of Electrical Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - K W West
- Department of Electrical Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - D M Zumbühl
- Departement Physik, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland.
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Camenzind LC, Yu L, Stano P, Zimmerman JD, Gossard AC, Loss D, Zumbühl DM. Hyperfine-phonon spin relaxation in a single-electron GaAs quantum dot. Nat Commun 2018; 9:3454. [PMID: 30150721 PMCID: PMC6110844 DOI: 10.1038/s41467-018-05879-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/30/2018] [Indexed: 12/05/2022] Open
Abstract
Understanding and control of the spin relaxation time T1 is among the key challenges for spin-based qubits. A larger T1 is generally favored, setting the fundamental upper limit to the qubit coherence and spin readout fidelity. In GaAs quantum dots at low temperatures and high in-plane magnetic fields B, the spin relaxation relies on phonon emission and spin-orbit coupling. The characteristic dependence T1 ∝ B-5 and pronounced B-field anisotropy were already confirmed experimentally. However, it has also been predicted 15 years ago that at low enough fields, the spin-orbit interaction is replaced by the coupling to the nuclear spins, where the relaxation becomes isotropic, and the scaling changes to T1 ∝ B-3. Here, we establish these predictions experimentally, by measuring T1 over an unprecedented range of magnetic fields-made possible by lower temperature-and report a maximum T1 = 57 ± 15 s at the lowest fields, setting a record electron spin lifetime in a nanostructure.
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Affiliation(s)
- Leon C Camenzind
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Liuqi Yu
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
| | - Peter Stano
- Center for Emergent Matter Science, RIKEN, Saitama, 351-0198, Japan
- Department of Applied Physics, School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
- Institute of Physics, Slovak Academy of Sciences, 845 11, Bratislava, Slovakia
| | - Jeramy D Zimmerman
- Materials Department, University of California, Santa Barbara, CA, 93106, USA
- Physics Department, Colorado School of Mines, Golden, CO, 80401, USA
| | - Arthur C Gossard
- Materials Department, University of California, Santa Barbara, CA, 93106, USA
| | - Daniel Loss
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
- Center for Emergent Matter Science, RIKEN, Saitama, 351-0198, Japan
| | - Dominik M Zumbühl
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
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