scholarly journals New mechanism and exact theory of superconductivity from strong repulsive interaction

2021 ◽  
Vol 7 (30) ◽  
pp. eabh2233
Author(s):  
Valentin Crépel ◽  
Liang Fu
Keyword(s):  
Pairing Symmetry ◽  
Charge Carriers ◽  
General Mechanism ◽  
Repulsive Interaction ◽  
Fermi Systems ◽  
Fermi Temperature ◽  
Spin Polarized ◽  
Atomic Limit ◽  
Theory Of Superconductivity ◽  
Quantitative Formula

We introduce a general mechanism for superconductivity in Fermi systems with strong repulsive interaction. Because kinetic terms are small compared to the bare repulsion, the dynamics of charge carriers is constrained by the presence of other nearby carriers. By treating kinetic terms as a perturbation around the atomic limit, we show that pairing can be induced by correlated multiparticle tunneling processes that favor two itinerant carriers to be close together. Our analytically controlled theory provides a quantitative formula relating Tc to microscopic parameters, with maximum Tc reaching about 10% of the Fermi temperature. Our work demonstrates a powerful method for studying strong coupling superconductivity with unconventional pairing symmetry. It also offers a realistic new route to realizing finite angular momentum superfluidity of spin-polarized fermions in optical lattice.

scholarly journals Counter-propagating charge transport in the quantum Hall effect regime

Science ◽  
2019 ◽  
Vol 363 (6422) ◽  
pp. 54-57 ◽  
Author(s):  
Fabien Lafont ◽  
Amir Rosenblatt ◽  
Moty Heiblum ◽  
Vladimir Umansky
Keyword(s):  
Hall Effect ◽  
Quantum Hall Effect ◽  
Electron Gas ◽  
Quantum Hall ◽  
Charge Carriers ◽  
Perpendicular Magnetic Field ◽  
Quantum Hall Regime ◽  
Hall Regime ◽  
Spin Polarized ◽  
Conjugate States

The quantum Hall effect, observed in a two-dimensional (2D) electron gas subjected to a perpendicular magnetic field, imposes a 1D-like chiral, downstream, transport of charge carriers along the sample edges. Although this picture remains valid for electrons and Laughlin’s fractional quasiparticles, it no longer holds for quasiparticles in the so-called hole-conjugate states. These states are expected, when disorder and interactions are weak, to harbor upstream charge modes. However, so far, charge currents were observed to flow exclusively downstream in the quantum Hall regime. Studying the canonical spin-polarized and spin-unpolarized v = 2/3 hole-like states in GaAs-AlGaAs heterostructures, we observed a significant upstream charge current at short propagation distances in the spin unpolarized state.

scholarly journals Zero-temperature relaxation in spin-polarized Fermi systems

1997 ◽  
Vol 23 (5) ◽  
pp. 411-419 ◽  
Author(s):  
A. E. Meyerovich ◽  
J. H. Naish ◽  
J. R. Owers-Bradley ◽  
A. Stepaniants
Keyword(s):  
Zero Temperature ◽  
Fermi Systems ◽  
Spin Polarized ◽  
Temperature Relaxation

Tunneling of spin-polarized charge carriers in La0.8Ag0.1MnO3+δ film with variant structure: Magnetotransport and magnetooptical data

2005 ◽  
Vol 31 (6) ◽  
pp. 484-487 ◽  
Author(s):  
Yu. P. Sukhorukov ◽  
A. V. Telegin ◽  
E. A. Gan’shina ◽  
N. N. Loshkareva ◽  
A. R. Kaul’ ◽  
...  
Keyword(s):  
Charge Carriers ◽  
Spin Polarized ◽  
Variant Structure

scholarly journals Ferromagnetism and spin-polarized charge carriers inIn2O3thin films

2009 ◽  
Vol 79 (16) ◽  
Author(s):  
Raghava P. Panguluri ◽  
P. Kharel ◽  
C. Sudakar ◽  
R. Naik ◽  
R. Suryanarayanan ◽  
...  
Keyword(s):  
Charge Carriers ◽  
Spin Polarized

Spin dynamics in spin-polarized Fermi systems

1995 ◽  
Vol 101 (3-4) ◽  
pp. 803-808
Author(s):  
A. E. Meyerovich ◽  
S. Stepaniants ◽  
F. Laloë
Keyword(s):  
Spin Dynamics ◽  
Fermi Systems ◽  
Spin Polarized

Diffusion in Metals, Quasicrystals, and Intermetallic Compounds

1998 ◽  
Vol 527 ◽  
Author(s):  
H. Mehrer ◽  
Th. Zumkley ◽  
M. Eggersmann ◽  
R. Galler ◽  
M. Salamon
Keyword(s):  
Temperature Regime ◽  
Diffusion Problem ◽  
Solute Diffusion ◽  
General Mechanism ◽  
Repulsive Interaction ◽  
Transition Elements ◽  
Self Diffusion ◽  
Number Of Factors ◽  
Recent Developments ◽  
Exponential Factors

ABSTRACTIn this paper recent developments of diffusion in three related areas will be reviewed: The first part is devoted to self- and solute diffusion in metals with particular emphasis on Al. Contrary to most other metallic solvents, diffusion of transition elements in Al is anomalous in several respects: diffusion is very slow, activation enthalpies, pre-exponential factors and activation volumes are unusually high. By contrast, non-transition elements in Al show more or less normal solute diffusion behaviour. The anomalous behaviour is attributed to a strong repulsive interaction between transition metal solutes and vacancies. Ab-initio calculations could help to understand this well-documented diffusion problem in detail.In the second part very recent diffusion studies on single crystals of the Al-base quasicrystalline intermetallic compound Al-Pd-Mn will be discussed. Diffusion of Zn, Ge, Mn, Fe, Co, Pd and Au has been studied by various groups. At least in the high-temperature regime diffusion in the quasicrystal – despite some differences in detail – shows striking similarities to diffusion in Al, for which a vacancy-type mechanism is generally accepted. The activation volumes of +0.67 and +0.74 atomic volumes measured for Mn- and Zn-diffusion in Al-Pd-Mn strongly favour a vacancy mechanism as well. For the low temperature regime of Pd and Au diffusion the possibility of a phason-related mechanism is discussed.The third part deals with recent investigations of iron-aluminides and iron-silicides for which Fe self-diffusion and diffusion of selected foreign elements (Ge in Fe–Si, In and Zn in Fe–Al) has been investigated. There is no doubt that vacancies mediate the diffusion process. Within this general mechanism a number of factors like the crystal structure, the state of order, the composition, and the type of bonding have strong influence on diffusion. Such factors are discussed also in connection with results from positron annihilation and M6ssbauer spectroscopy.

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