Opis projektu badawczego i pracy doktorskiej

Topologiczne własności pewnych stanów nadprzewodzących wzbudzają ogromne zainteresowanie z uwagi na ich potencjalne zastosowanie w komputerach kwantowych. Obiecującą platformą dla nadprzewodnictwa topologicznego i możliwej obecności kwazicząstek Majorany są nadprzewodniki chiralne — trójwymiarowe materiały topologiczne, w których pary Coopera o niezerowym momencie pędu krążą wokół wyróżnionej osi, w ten sposób spontanicznie łamiąc symetrię odwrócenia czasu. Tak wyjątkowe właściwości, atrakcyjne z punktu widzenia nauk podstawowych i stosowanych, motywują fizyków do poszukiwania nadprzewodnictwa topologicznego. Jednak potencjalnych materiałów jest niewiele, a sama realizacja chiralnego nadprzewodnictwa jest nadal przedmiotem intensywnej debaty.

Projekt ma na celu zbadanie zależności temperaturowej dolnego pola krytycznego Hc1 w potencjalnych nadprzewodnikach chiralnych wykorzystując innowacyjne mikroczujniki Halla o wysokiej rozdzielczości przestrzennej. Planowane są pomiary Hc1(T) do temperatur tak niskich jak 0,007 K, ponieważ badania głęboko w stanie nadprzewodzącym mogą potwierdzić lub wykluczyć możliwe symetrie parametru porządku. Planuje się również zbadać wpływ naprężenia jednoosiowego, ponieważ własności topologiczne są nieodłącznie związane z symetrią sieci krystalicznej, którą można w ten sposób silnie modyfikować.

Projekt skupia się na najnowszych odkryciach w dziedzinie nadprzewodnictwa chiralnego, tj. 4Hb-TaS2 (Tc = 2,7 K, oddziaływania van der Waalsa), UTe2 (Tc ≃ 1,7 K, fluktuacje ferromagnetyczne) i CeRh2As2 (Tc ≃ 0,3 K, lokalna niecentrosymmetryczność), z jednej strony, z drugiej zaś interesują nas kanoniczne związki ciężkofermionowe CeCu2Si2 (Tc ≃ 0,6 K) i PrOs4Sb12 (Tc ≃ 1,8 K).  Dodatkowe informacje można znaleźć w publikacji J. Juraszek, R.Wawryk, Z. Henkie, M. Konczykowski, and T. Cichorek, Symmetry of Order Parameters in Multiband Superconductors LaRu4As12 and PrOs4Sb12 Probed by Local Magnetization Measurements, Phys. Rev. Lett. 124 (2020) 027001 oraz na stronie https://cms.intibs.pl/zespoly/lfnt.

 
Wszelkie pytania prosimy kierować do Kierownika projektu prof. dr. hab. Tomasza Cichorka (t.cichorek@intibs.pl, tel. +48 71 395 4265).

 
Dane osobowe

Pani/Pana dane osobowe są gromadzone i przetwarzane przez Wrocławską Szkołę Instytutów Polskiej Akademii Nauk we Wrocławiu zgodnie z informacją o przetwarzaniu danych osobowych dostępną na stronie: https://bip.intibs.pl/artykuly/173/rodo. 
 

SPECIAL RECRUITMENT TO THE DOCTORAL SCHOOL FOR PhD STUDENT -  SCHOLARSHIP HOLDER IN A RESEARCH PROJECT

INSTITUTION:  Institute of Low Temperature and Structural Research, Polish Academy of Sciences, Wrocław Doctoral School of Institutes of Polish Academy of Sciences

POSITION: PhD student (NCN research project OPUS 23)

SCIENTIFIC DISCIPLINE: physics

DATE OF ANNOUNCEMENT: 2nd August 2023

APPLICATION DEADLINE: 4th September 2023

DATE OF COMPETITION SETTLEMENT: up to 7 days after an interview

DATE OF COMMENCEMENT OF EDUCATION AND PARTICIPATION IN THE PROJECT: 1st October 2023

LINK TO WSD IPAN WEBSITE: http://wsdipan.intibs.pl 

LINK TO INTiBS PAN WEBSITE: http://intibs.pl

KEY WORDS: low-temperature physics, unconventional superconductivity


Competition Announcement

Wrocław Doctoral School of Institutes of Polish Academy of Sciences (WDS IPAS) announces a special recruitment for a PhD student – scholarship holder in the research project Constraints on the order parameter in candidate chiral superconductors from local magnetization measurements, carried out on behalf of the National Science Center (program OPUS 23, No. 2022/45/B/ST3/04117) in the Laboratory for Low-Temperature Physics, Division of Magnetic Research, Institute of Low Temperature and Structure Research, Polish Academy of Sciences in Wroclaw. 

Recruitment is conducted in accordance with the Rules of Recruitment to the Wrocław Doctoral School of Institutes of Polish Academy of Sciences for 2023/2024 academic year https://www.intibs.pl/goto/WSD_rekrutacja_2023-24  and the regulations of Awarding Funds for the Implementation of Tasks Financed by the National Science Center (NCN) in the Area of Research Projects, adopted by the Resolution of the Council of the National Science Center No. 79/2021.

Requirements

·         a master's degree or an equivalent degree in physics, materials engineering or related disciplines entitling to study at a doctoral school (or persons who will obtain this title before starting education, i.e. before October 1, 2023) a diploma (or a certificate from a university confirming master's degree or equivalent) before October 1, 2023 (failure to meet this requirement will result in removal from the list of doctoral students), 

·         scientific interest in low-temperature  experimental physics, cryogenics, etc.,

·         motivation to scientific work, reliability, independence, teamwork skills, creativity, high personal culture,

·         ability to fulfill admission requirements for the Wrocław Doctoral School of Institutes of Polish Academy of Sciences.

 
Responsibilities

·         implementation, within 48 months, the educational program of the doctoral school followed by completing a doctoral degree (at the latest within 12 months after the end of the project),

·         implementation of an individual research plan, consistent with the research project proposed.


Scholarship

The OPUS 23 doctoral scholarship will be paid for 48 months in amount of 4000 PLN per month. Note that the amount will be reduced by the cost of mandatory social security contributions, etc., about 24%.


Required documents

·         A candidate is requested to submit documents specified in the rules of recruitment for the Wrocław Doctoral School of Institutes of the Polish Academy of Sciences for the academic year 2023/24  https://www.intibs.pl/goto/WSD_rekrutacja_2023-24 . The documents should be submitted using one of the available options  by 4 September 2023:

·         in person at the School’s Secretariat Office at the Institute of Low Temperature and Structure Research of the Polish Academy of Sciences, 2 Okólna St. in Wrocław, from 9 am to 3 pm,

·         by registered mail or courier (the date on which the Secretariat Office received the documents is considered to be the delivery date) to the following address: WSD IPAN, ul. Okólna 2, 50-422 Wrocław,

·         by email to the address wsdipan@intibs.pl. Please be informed that the original documents should be delivered before the studies start.

·         In the subject line of an application please provide: OPUS-23-TC.

 
Description of the research project

In the past years, the revealed significance of the topological nature of certain superconducting states has attracted great interest in condensed matter physics because of its potential application for topological fault-tolerant quantum computation. A promising platform for topological superconductivity and emergent Majorana quasiparticles are chiral superconductors – bulk topological materials with finite angular momentum Cooper pairs circulating around a unique chiral axis, thereby spontaneously breaking time-reversal symmetry. Such unique properties, attractive from the viewpoints of basic and applied science, triggered tremendous efforts for searching for topological superconductivity. However, naturally occurring candidate materials are scarce and the realization of chiral superconductivity is still under intensive debate. 

Main research task is intended to investigate the temperature dependence of the field of first flux penetration of leading candidate materials for chiral superconductivity utilizing a new innovative Hall micromagnetometry with a high spatial resolution. We propose measurements of the lower critical field Hc1 down to temperatures as low as 0.007 K, since investigations deep in the superconducting state can validate or rule out a subset of possible superconducting order parameters. We also plan to explore effect of uniaxial stress, since unconventional superconducting order parameters are inherently connected to the symmetry of the underlying crystal lattice that can be reduced under strain. 

We focus on the newest discoveries in the field, i.e., 4Hb-TaS2 (Tc = 2.7 K, van der Waals material), UTe2 (Tc ≃ 1.7 K, ferromagnetic fluctuations), and CeRh2As2 (Tc ≃ 0.3 K, nonsymmorphic symmetry) and from one side, while we are interested in canonical heavy-fermion compounds CeCu2Si2 (Tc ≃ 0.6 K, first-ever heavy-fermion superconductor discovered in 1979) and PrOs4Sb12 (Tc ≃ 1.8 K, first Pr-based superconductor discovered in 2002) on the other. Supplementary information can be found in the paper by  J. Juraszek, R.Wawryk, Z. Henkie, M. Konczykowski, and T. Cichorek, Symmetry of Order Parameters in Multiband Superconductors LaRu4As12 and PrOs4Sb12 Probed by Local Magnetization Measurements, Phys. Rev. Lett. 124 (2020) 027001  as well as at https://cms.intibs.pl/zespoly/lfnt.

 
Additional information

For additional information, please contact the Project Manager, prof. dr hab. Tomasz Cichorek (t.cichorek@intibs.pl, tel. +48 71 395 4265).

 
Personal information

Candidates' personal data are collected and processed by the Institute of Low Temperature and Structure Research of Polish Academy of Sciences in Wrocław in accordance with the information on personal data processing available at https://bip.intibs.pl/artykuly/173/rodo.