Home > Press > Detection of atomic scale structure of Cooper-pairs in a high-TC superconductor: Researchers from Seoul National University and the Center for Correlated Electron Systems within the Institute for Basic Science discover a Cooper-pair density wave at an atomic level
Figure 1.A: Typical 35 nm X 35 nm topographic image T(r) at BiO termination layer of BSCCO (crystal "supermodulation" runs vertically).
B: Typical g(E)=dI/dV(E=eV) differential tunnel conductance spectra of superconducting Bi2Sr2CaCu2O8. The maximum energy gap is determined from half the distance between peaks in each spectrum. C: Spatial arrangement of ƒ´(r) (gapmap) for p~17% Bi2Sr2CaCu2O8 samples studied here in same 35 nm X 35 nm FOV as A. D: Magnitude of Fourier transform of c, |? ?(?)| (crosses are at q=(π/a0,0);(0,π /a0)) E: As typical26, a single in equivalent peak due to the crystal "supermodulation" is observed (blue arrow). F: Simultaneously measured magnitude of Δ(q) and t (q) from d,e along the (1,1) direction. Their primary peaks coincide exactly. CREDIT: IBS |
Abstract:
The international scientific team reported the first ever observation of the atomic scale structure of Cooper-pairs in the superconductor Bi2Sr2CaCu2O8+x: a material belonging to the family of high-temperature (High-TC) superconductors bismuth strontium calcium copper oxide, or BSCCO. This detection is a breakthrough in the understanding of the ever elusive high-TC superconductivity phenomena.
Condensing fermions into one macroscopic quantum state
Conventional superconductors are not a recent discovery; conversely, they have been in commercial use for a number of decades but the extreme temperatures required, less than -263oC, prove difficult to attain and maintain, as opposed to high-TC superconductors where more manageable temperatures of -196oC are required. Superconductivity occurs under certain temperatures: electrons form pairs and suddenly the electrical resistance drops to zero and the magnetic field inside of the material is repelled.
In nature, there are examples of emergence of macroscopic quantum states - superfluidity, Bose-Einstein condensation for example- where bosonic particles (bosons) condense and form one macroscopic quantum entity. Electrons which are fermions--not bosons--cannot condense into one entity. However, under extremely low temperatures fermions cleverly combine into pairs and act as if they are bosons; they condense into one state and form yet another kind of macroscopic quantum phase - superconductivity.
Overcoming severe difficulties
The international scientific team had to overcome difficulties in creating an extreme environment. The process of detecting electrons is incredibly intricate, even when using advanced modern scientific machinery. Professor Jinho Lee, leader of the project, explains: "Even detecting electrons in atomic resolution using a scanning tunneling microscope (STM) requires extremely low temperatures, low vibrations and a vacuumed environment to prevent any decay in the tip of the microscope or the sample as well as to minimize any electrical noise. Detecting pairs is exponentially more difficult since the normal metal tip can only detect electrons and is unable to probe electron pairs. Naturally one needs to use a sharp, durable superconducting tip which is very challenging to make. Many researchers tried and failed. We solved this arduous problem by creating a superconducting tip in-situ using the same material as the sample. Cooper pairs can be detected due to the Josephson effect between the superconducting tip and sample. By using this Scanning Josephson Tunneling Microscopy, we were able to directly measure Cooper-pairs in atomic resolution for the first time."
Tunneling through barriers and looking toward the future
The Josephson effect is directly linked to superconductivity. Two superconducting materials, separated by a very thin barrier, can overlap their wave functions and Cooper pairs can tunnel through the barrier: This is known as the Josephson effect. Using the Scanning Josephson Tunneling Microscope, the team detected, at an atomic scale, the Cooper-pair tunneling through the barrier between the superconducting materials.
The team's results, published in Nature, announced the world's first measurement of atomic scale structure of Cooper-pairs. The implications of this discovery might not reverberate for many years in commercial applications of superconductors, but there is no doubt that the team altered the future path of superconductor research.
####
For more information, please click here
Contacts:
Dahee Carol Kim
82-428-788-133
Copyright © Institute for Basic Science
If you have a comment, please Contact us.Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Related Links |
Related News Press |
Quantum Physics
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
Physics
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
'Sudden death' of quantum fluctuations defies current theories of superconductivity: Study challenges the conventional wisdom of superconducting quantum transitions January 12th, 2024
News and information
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Superconductivity
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
Possible Futures
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
With VECSELs towards the quantum internet Fraunhofer: IAF achieves record output power with VECSEL for quantum frequency converters April 5th, 2024
Chip Technology
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
Discoveries
Chemical reactions can scramble quantum information as well as black holes April 5th, 2024
New micromaterial releases nanoparticles that selectively destroy cancer cells April 5th, 2024
Utilizing palladium for addressing contact issues of buried oxide thin film transistors April 5th, 2024
Announcements
NRL charters Navy’s quantum inertial navigation path to reduce drift April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Simulating magnetization in a Heisenberg quantum spin chain April 5th, 2024
Discovery points path to flash-like memory for storing qubits: Rice find could hasten development of nonvolatile quantum memory April 5th, 2024
The latest news from around the world, FREE | ||
Premium Products | ||
Only the news you want to read!
Learn More |
||
Full-service, expert consulting
Learn More |
||