Quant-ERA: Topologically protected states in double nanowire superconductor hybrids  Page description

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Details of project

  
Identifier
127900
Type NN
Principal investigator Csonka, Szabolcs
Title in Hungarian Quant-ERA: Topologikusan védett állapotok szupravezető dupla nanopálca hibrid rendszerekben
Title in English Quant-ERA: Topologically protected states in double nanowire superconductor hybrids
Keywords in Hungarian nanopálca, szupravezetés, majorana fermion, parafermion
Keywords in English nanowire, superconductivity, majorana fermions, parafermions
Discipline
Physics (Council of Physical Sciences)100 %
Ortelius classification: Condensed matter properties
Panel Physics 1
Department or equivalent Department of Physics (Budapest University of Technology and Economics)
Participants Fülöp, Gergő
Kürtössy, Olivér
Starting date 2018-04-01
Closing date 2022-03-31
Funding (in million HUF) 46.410
FTE (full time equivalent) 3.03
state closed project
Summary in Hungarian
A kutatás összefoglalója, célkitűzései szakemberek számára
Itt írja le a kutatás fő célkitűzéseit a témában jártas szakember számára.
Topological quantum computing (TQC) is an emerging field with strong benefits for prospective applications, since it provides an elegant way around decoherence. The theory of TQC progressed very rapidly during the last decade from various qubit realizations to scalable computational protocols. However, experimental realization of these concepts lags behind. Important experimental milestones have been achieved recently, by demonstrating the first signatures of Majorana states which are the simplest non-Abelian anyons. However, to realize fully topologically protected universal quantum computation, more exotic anyons, such as parafermions are required. Thus, the unambiguous demonstration of parafermion states will have a great impact on the development of universal quantum computation.
The experimental realization of parafermions is challenging, since they are based on the combination of various ingredients, such as crossed Andreev reflection, electron-electron or spin-orbit interaction, and high quality quantum conductors. Thus, the investigation of all these ingredients is essential and timely to achieve further experimental progress. The team of SuperTop is composed of six leading groups with strong and complementary experimental background in these areas with the aim to realize parafermions in double nanowire-based hybrid devices (DNW) for the first time.

Mi a kutatás alapkérdése?
Ebben a részben írja le röviden, hogy mi a kutatás segítségével megválaszolni kívánt probléma, mi a kutatás kiinduló hipotézise, milyen kérdéseket válaszolnak meg a kísérletek.
The main objectives of SuperTop are:
a) development of different DNW geometries, which consist of two parallel 1D spin-orbit nanowires coupled by a thin superconductor stripe and
b) investigation of the emerging exotic bound states at the superconductor/semiconductor interface of the DNW.
SuperTop first grows state-of-the-art InAs and InSb based nanostructures, in particular InAs nanowires (NWs) with in-situ grown epitaxial superconducting layer, NWs with built-in InP barriers and InSb nanoflakes. Based on these high quality materials, different device geometries of DNW are fabricated and the emerging novel states are investigated. The topological character, quantum phase transition, coherence time, coupling strength to QED as key features of the engineered new states are planned to be addressed by various cutting-edge low temperature measurement techniques (e.g. non-local spectroscopy, noise, current-phase relationship measurement or integration into coplanar resonators).

Mi a kutatás jelentősége?
Röviden írja le, milyen új perspektívát nyitnak az alapkutatásban az elért eredmények, milyen társadalmi hasznosíthatóságnak teremtik meg a tudományos alapját. Mutassa be, hogy a megpályázott kutatási területen lévő hazai és a nemzetközi versenytársaihoz képest melyek az egyediségei és erősségei a pályázatának!
The research project of SuperTop is strongly linked to various targeted outcomes of the QuantERA call. Our advanced multidisciplinary work aims to engineer the central building block of a new architecture of quantum computation, so called parafermions. In order to do so, SuperTop investigates novel superconductor/semiconductor hybrid devices to realize engineered topologically protected quantum systems. Thereby our activity will contribute to develop novel ideas in quantum science, which could lead to built-in protection of quantum information as a radically enhanced functionality. The expected topological protection will be a game changer and will help to realize universal quantum computing, which is one of the pillars of the EU Quantum Manifesto.

A kutatás összefoglalója, célkitűzései laikusok számára
Ebben a fejezetben írja le a kutatás fő célkitűzéseit alapműveltséggel rendelkező laikusok számára. Ez az összefoglaló a döntéshozók, a média, illetve az érdeklődők tájékoztatása szempontjából különösen fontos az NKFI Hivatal számára.
Decoherence due to a noisy environment is a major challenge for all quantum computation architectures. There are strategies to handle decoherence, such as performing the operations fast within the coherence time or using quantum feedback, but their application and scaling run into further limitations. The emerging field of topological quantum computing (TQC) holds a remarkable promise to overcome this serious issue, since the built-in topological protection of the system allows error-free quantum operations. The theory of TQC progressed very rapidly during the last decade, as various qubit realizations and computational protocols were proposed and investigated. However, experimental realization of these concepts lags well behind the theory.
A recent important experimental milestone was the demonstration of the signatures of Majorana states in semiconductor/superconductor hybrid devices. However, quantum operations with Majorana modes do not allow to realize universal topologically protected quantum gates required for error-free quantum operations. If the architecture is based on more exotic excitations called parafermions, then more robust topological protection and richer fault-tolerant qubit rotations can be achieved. Parafermions are generalized (fractional) Majorana fermions, and they are the building blocks of Fibonacci anyons, which allow to build the ultimate fully universal topological quantum computing hardware.
The targeted breakthrough of SuperTop is to realize parafermions for the first time. Towards this goal special double nanowire setup will be developed and emerging exotic bound states will be investigated with various experimental techniques.
Summary
Summary of the research and its aims for experts
Describe the major aims of the research for experts.
Topological quantum computing (TQC) is an emerging field with strong benefits for prospective applications, since it provides an elegant way around decoherence. The theory of TQC progressed very rapidly during the last decade from various qubit realizations to scalable computational protocols. However, experimental realization of these concepts lags behind. Important experimental milestones have been achieved recently, by demonstrating the first signatures of Majorana states which are the simplest non-Abelian anyons. However, to realize fully topologically protected universal quantum computation, more exotic anyons, such as parafermions are required. Thus, the unambiguous demonstration of parafermion states will have a great impact on the development of universal quantum computation.
The experimental realization of parafermions is challenging, since they are based on the combination of various ingredients, such as crossed Andreev reflection, electron-electron or spin-orbit interaction, and high quality quantum conductors. Thus, the investigation of all these ingredients is essential and timely to achieve further experimental progress. The team of SuperTop is composed of six leading groups with strong and complementary experimental background in these areas with the aim to realize parafermions in double nanowire-based hybrid devices (DNW) for the first time.

What is the major research question?
Describe here briefly the problem to be solved by the research, the starting hypothesis, and the questions addressed by the experiments.
The main objectives of SuperTop are:
a) development of different DNW geometries, which consist of two parallel 1D spin-orbit nanowires coupled by a thin superconductor stripe and
b) investigation of the emerging exotic bound states at the superconductor/semiconductor interface of the DNW.
SuperTop first grows state-of-the-art InAs and InSb based nanostructures, in particular InAs nanowires (NWs) with in-situ grown epitaxial superconducting layer, NWs with built-in InP barriers and InSb nanoflakes. Based on these high quality materials, different device geometries of DNW are fabricated and the emerging novel states are investigated. The topological character, quantum phase transition, coherence time, coupling strength to QED as key features of the engineered new states are planned to be addressed by various cutting-edge low temperature measurement techniques (e.g. non-local spectroscopy, noise, current-phase relationship measurement or integration into coplanar resonators).

What is the significance of the research?
Describe the new perspectives opened by the results achieved, including the scientific basics of potential societal applications. Please describe the unique strengths of your proposal in comparison to your domestic and international competitors in the given field.
The research project of SuperTop is strongly linked to various targeted outcomes of the QuantERA call. Our advanced multidisciplinary work aims to engineer the central building block of a new architecture of quantum computation, so called parafermions. In order to do so, SuperTop investigates novel superconductor/semiconductor hybrid devices to realize engineered topologically protected quantum systems. Thereby our activity will contribute to develop novel ideas in quantum science, which could lead to built-in protection of quantum information as a radically enhanced functionality. The expected topological protection will be a game changer and will help to realize universal quantum computing, which is one of the pillars of the EU Quantum Manifesto.

Summary and aims of the research for the public
Describe here the major aims of the research for an audience with average background information. This summary is especially important for NRDI Office in order to inform decision-makers, media, and others.
Decoherence due to a noisy environment is a major challenge for all quantum computation architectures. There are strategies to handle decoherence, such as performing the operations fast within the coherence time or using quantum feedback, but their application and scaling run into further limitations. The emerging field of topological quantum computing (TQC) holds a remarkable promise to overcome this serious issue, since the built-in topological protection of the system allows error-free quantum operations. The theory of TQC progressed very rapidly during the last decade, as various qubit realizations and computational protocols were proposed and investigated. However, experimental realization of these concepts lags well behind the theory.
A recent important experimental milestone was the demonstration of the signatures of Majorana states in semiconductor/superconductor hybrid devices. However, quantum operations with Majorana modes do not allow to realize universal topologically protected quantum gates required for error-free quantum operations. If the architecture is based on more exotic excitations called parafermions, then more robust topological protection and richer fault-tolerant qubit rotations can be achieved. Parafermions are generalized (fractional) Majorana fermions, and they are the building blocks of Fibonacci anyons, which allow to build the ultimate fully universal topological quantum computing hardware.
The targeted breakthrough of SuperTop is to realize parafermions for the first time. Towards this goal special double nanowire setup will be developed and emerging exotic bound states will be investigated with various experimental techniques.




 

Final report

  
Results in Hungarian
Topologius hibrid nanoeszközök egzotikus kötött állapotai ígéretesek kvantumszámítógép építőköveinek. Kutatómunkánk során olyan nanoeszközöket fejlesztettünk és vizsgáltunk, amikben a spin-pálya kölcsönhatás, párhuzamos egy dimenziós vezetők, kereszt Andrejev reflexió és elektron elektron kölcsönhatás új kötött állapotokhoz vezet. Új topologikus szerkezetet, ún. mágneses Weyl-pontokat sikerült azonosítanunk erős spin-pálya kölcsönhatással bíró InAs nanopálckban létrehozott csatolt mesterséges atom rendszerben. Néhány atomi réteg vastag alagútátmenettel elválasztott szonda segítségével vizsgáltuk a szupravezető gap struktúrát egy dimenziós nanovezetékben. Kvantumeszközöket fejlesztettünk új két InAs nanopálcán alapuló nanoszerkezetből, amiket epitaxiálisan növesztett szupravezető réteg kapcsol össze. Az erős szupravezető proximity effektusnak köszönhetően, elsőként azonosítottunk ezen dupla pálcákban Andrejev-molekuláris állapotot és feltártuk a molekula fázisdiagramját. Elsőként vizsgáltuk a Yu-Shiba-Rusinov (YSR) állapot térbeli kiterjedését mesterséges atomot csatolva szupravezetőhöz. Az állapot kiterjedése, meglepő módon, jelentősen meghaladta a normál atomoknál megszokott méretet elérve az 50-200nm-t. A mai nanotechnológiai eljárásokkal ilyen távolságra mesterséges atomok létrehozhatóak rutinszinten, megnyitva az utat YSR láncok létrehozásához, ami topologikus kvantumszámítógép architektúrák fontos építőköve.
Results in English
Exotic bound states in engineered topological superconductor hybrid nanodevices are promising for quantum computation purpose. In this project devices are developed and investigated where the interplay of spin-orbit interaction, parallel 1D conducting channels, crossed-Andreev reflection and e-e interaction generates novel bound states. We have identified novel topological structure, so-called magnetic Weyl points in coupled quantum dots realized in InAs nanowires which has strong spin-orbit interaction. We explored superconducting subgap spectrum of 1D nanowires with a local probe realized with a few atomic thin tunnel barrier. We developed quantum devices based on a novel nanostructure, a double InAs nanowires connected with epitaxial superconducting layer. Thanks to the strong superconducting proximity effect we identified for the first time Andreev-molecular states in double nanowires and also explored the phase diagram of this molecule. We also studied for the first time the spatial extension of the Yu-Shiba-Rusinov (YSR) state, which forms in superconductor attached to an artificial atom. Surprisingly the state is significantly larger than for normal atoms, its dimension reaches 50-200nm. With state-of-the-art nanotechnology artificial atoms can be routinely fabricated at such distances, which opens the way to realize YSR chains, an important building block of topological quantum architectures.
Full text https://www.otka-palyazat.hu/download.php?type=zarobeszamolo&projektid=127900
Decision
Yes





 

List of publications

  
Zoltán Scherübl, Gergő Fülöp, Jörg Gramich, András Pályi, Christian Schönenberger, Jesper Nygård, and Szabolcs Csonka: From Cooper pair splitting to nonlocal spectroscopy of a Shiba state, Phys. Rev. Research 4, 023143, 2022
Z. Scherübl, A. Pályi, Gy. Frank, I. E. Lukács, G. Fülöp, B. Fülöp, J. Nygård, K. Watanabe, T. Taniguchi, G. Zaránd & Sz. Csonka: Observation of spin–orbit coupling induced Weyl points in a two-electron double quantum dot, Nature Communications Physics, 2, 108, 2019
Z. Scherübl, A. Pályi, Sz: Csonka: Transport signatures of an Andreev molecule in a quantum dot -- superconductor -- quantum dot setup, Belstein J. of Nanotechnology, 2019
Z. Scherübl, A. Pályi, Gy. Frank, I. E. Lukács, G. Fülöp, B. Fülöp, J. Nygård, K. Watanabe, T. Taniguchi, G. Zaránd & Sz. Csonka: Observation of spin–orbit coupling induced Weyl points in a two-electron double quantum dot, Nature Communications Physics, 2, 108, 2019
Z. Scherübl, A. Pályi, Sz: Csonka: Transport signatures of an Andreev molecule in a quantum dot -- superconductor -- quantum dot setup, Belstein J. of Nanotechnology, 10, 363, 2019
Scherübl Zoltán, Fülöp Gergő, Moca Cătălin Paşcu, Gramich Jörg, Baumgartner Andreas, Makk Péter, Elalaily Tosson, Schönenberger Christian, Nygård Jesper, Zaránd Gergely, Csonka Szabolcs: Large spatial extension of the zero-energy Yu–Shiba–Rusinov state in a magnetic field, NATURE COMMUNICATIONS 11: (1) 1834, 2020
T. Elalaily, O. Kürtössy, V. Zannier, Z. Scherübl, I. Endre Lukács, P. Srivastava, F. Rossi, L. Sorba, Sz. Csonka, P. Mak: Probing proximity induced superconductivity in InAs nanowire using built-in barriers, Phys. Rev. Applied, 14, 044002, 2020
G. Frank, Z. Scherübl, S. Csonka, G. Zarand, A. Palyi: Magnetic degeneracy points in interacting spin systems: geometrical patterns, Phys. Rev. B, 101, 245409 (2020), 2020
Péter Kun, Bálint Fülöp, Gergely Dobrik, Péter Nemes-Incze, István Endre Lukács, Szabolcs Csonka, Chanyong Hwang & Levente Tapasztó: Robust quantum point contact operation of narrow graphene constrictions patterned by AFM cleavage lithography, npj 2D Materials and Applications, 2020
Zoltán Kovács-Krausz, Anamul Md Hoque, Péter Makk*, Bálint Szentpéteri, Mátyás Kocsis, Bálint Fülöp, Michael Vasilievich Yakushev, Tatyana Vladimirovna Kuznetsova, Oleg Evgenevich Tereshchenko, Konstantin Aleksandrovich Kokh, István Endre Lukács, Takashi Taniguchi, Kenji Watanabe, Saroj Prasad Dash, and Szabolcs Csonka: Electrically Controlled Spin Injection from Giant Rashba Spin–Orbit Conductor BiTeBr, Nano Lett. 20, 7, 4782–4791, 2020
Bálint Fülöp, Albin Márffy, Simon Zihlmann, Martin Gmitra, Endre Tóvári, Bálint Szentpéteri, Máté Kedves, Kenji Watanabe, Takashi Taniguchi, Jaroslav Fabian, Christian Schönenberger, Péter Makk, Szabolcs Csonka: Boosting proximity spin orbit coupling in graphene/WSe2 heterostructures via hydrostatic pressure, npj 2D Materials and Applications 5, 82, 2021
Olivér Kürtössy, Zoltán Scherübl, Gergő Fülöp, István Endre Lukács, Thomas Kanne, Jesper Nygård, Péter Makk, Szabolcs Csonka: Andreev Molecule in Parallel InAs Nanowires, Nano Letters, 21, 7929, 2021
Patrycja Tulewicz, Kacper Wrześniewski, Szabolcs Csonka, and Ireneusz Weymann: Large Voltage-Tunable Spin Valve Based on a Double Quantum Dot, Phys. Rev. Applied 16, 014029, 2021
Bálint Szentpéteri, Peter Rickhaus, Folkert K. de Vries, Albin Márffy, Bálint Fülöp, Endre Tóvári, Kenji Watanabe, Takashi Taniguchi, Andor Kormányos, Szabolcs Csonka, and Péter Makk: Tailoring the Band Structure of Twisted Double Bilayer Graphene with Pressure, Nano Letters, 21, 8777, 2021
Tosson Elalaily, Olivér Kürtössy, Zoltán Scherübl, Martin Berke, Gergő Fülöp, István Endre Lukács, Thomas Kanne, Jesper Nygård, Kenji Watanabe, Takashi Taniguchi, Péter Makk, Szabolcs Csonka: Gate-controlled supercurrent in an epitaxial Al/InAs nanowire, Nano Letters, 21, 9684, 2021
Thomas Kanne, Dags Olsteins, Mikelis Marnauza, Alexandros Vekris, Juan Carlos Estrada Saldana, Sara Loric, Rasmus D. Schlosser, Daniel Ross, Szabolcs Csonka, Kasper Grove-Rasmussen, Jesper Nygård: Double nanowires for hybrid quantum devices, Advanced Functional Materials, 32, 9, 2107926, 2022




 

Events of the project

  
2019-06-08 15:12:41
Résztvevők változása
2019-03-22 11:06:54
Résztvevők változása



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