Two-dimensional superconductivity at the (111)
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>LaAlO</mml:mi><mml:msub><mml:mrow /><mml:mn>3</mml:mn></mml:msub><mml:mo>/</mml:mo><mml:mi>SrTiO</mml:mi><mml:msub><mml:mrow /><mml:mn>3</mml:mn></mml:msub></mml:math>
 interface

Monteiro, A. M. R. V. L.; Groenendijk, Dirk J.; Groen, Inge; Bruijckere, Joeri de; Gaudenzi, Rocco; Zant, Herre S. J. van der; Caviglia, Andrea D.

doi:10.1103/physrevb.96.020504

Cited by 62 publications

(56 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…condition that the out-of-plane coherence length is larger than the SC thickness d SC ), providing the cusplike behavior around the parallel magnetic fields, as widely observed in various 2D systems including the amorphous or granular metal ultrathin SC films as well as the recently developed highly crystalline 2D superconductors near the SC critical temperature (T c ) [13][14][15][16][17][18][19][20]. Importantly, this 2D Tinkham's formula assumes that H c2 (θ ) is determined by the orbital effect in the entire θ region.…”

mentioning

confidence: 99%

Angle dependence of Hc2 with a crossover between the orbital and paramagnetic limits

Matsuoka

Nakano

Shitaokoshi

et al. 2020

Phys. Rev. Research

View full text Add to dashboard Cite

A pair-breaking mechanism of a superconductor under magnetic fields, namely, the origin of the upper critical field H c2 , can be categorized into the orbital effect and the paramagnetic effect, which have been separately discussed so far because the physical pictures are totally different. Here we propose a model that unifies these two origins into one formalism with a generalized physical picture. The obtained formula well describes the experimental results on the angle dependence of H c2 in a recently developed noncentrosymmetric superconductor, two-dimensional (2D) NbSe 2 , providing essential information on the spin states of Cooper pairs in 2D NbSe 2 . The proposed model is widely applicable to all superconductors, offering a powerful approach for comprehensive understanding of the origin of H c2 . Superconductivity is usually suppressed by application of external magnetic fields above the upper critical field H c2 . The origins of H c2 are classified into two pair-breaking effects, the orbital effect and the paramagnetic effect. In the limit of the strong orbital effect (the orbital limit), the kinetic energy loss due to the magnetic-field-driven cyclotron motion of electrons causes suppression of superconductivity by forming the vortices or Meissner current. In the paramagnetic limit, on the other hand, superconductivity is suppressed by the energy gain of the spin-aligned paramagnetic state, which exceeds the gain of the condensation energy of the Cooper pairs. Within the framework of the Bardeen-Cooper-Schrieffer (BCS) theory, this paramagnetic limit is called the Pauliparamagnetic limit and is set to be H P = 0

show abstract

mentioning

confidence: 99%

Angle dependence of Hc2 with a crossover between the orbital and paramagnetic limits

Matsuoka

Nakano

Shitaokoshi

et al. 2020

Phys. Rev. Research

View full text Add to dashboard Cite

show abstract

“…Recently, various groups have started to probe 2DEGs at oxide (111) surfaces and interfaces, for instance induced by photon [28] or ion [29,30] irradiation at the (111) STO surface, as well as that at the (111) LAO-STO interface [31][32][33][34][35]. Part of this interest stems from proposals for realizing topologically nontrivial phases along this growth direction [36][37][38][39][40][41][42][43].…”

mentioning

confidence: 99%

Magnetic and Nematic Orders of the Two-Dimensional Electron Gas at Oxide (111) Surfaces and Interfaces

Boudjada¹,

Wachtel²,

Paramekanti³

2018

Phys. Rev. Lett.

View full text Add to dashboard Cite

Recent experiments have explored two-dimensional electron gases (2DEGs) at oxide (111) surfaces and interfaces, finding evidence for hexagonal symmetry breaking in SrTiO_{3} at low temperature. We discuss many-body instabilities of such (111) 2DEGs, incorporating multiorbital interactions in the t_{2g} manifold which can induce diverse magnetic and orbital orders. Such broken symmetries may partly account for the observed nematicity, cooperating or competing with phonon mechanisms. We present an effective field theory for the interplay of magnetism and nematic charge order, and discuss implications of the nematicity for transport and superconductivity in (111) 2DEGs.

show abstract

“…Similarly, an in-plane magnetic field is found to have a significant impact on charge transport, leading to a large negative magnetoresistance in (001) 2DEGs over a range of densities 23,30,31 . More recent experiments have begun to create and probe 2DEGs at oxide (111) surfaces and interfaces [32][33][34][35][36][37][38][39][40][41] which have been proposed to host topological phases [42][43][44][45][46][47][48][49] . Such (111) interfaces typically lead to more tightly confined 2DEGs 50 .…”

Section: Introductionmentioning

confidence: 99%

Anisotropic magnetoresistance in multiband systems: Two-dimensional electron gases and polar metals at oxide interfaces

2019

View full text Add to dashboard Cite

Low density two-dimensional electron gases (2DEGs) with spin-orbit coupling are highly sensitive to an in-plane magnetic field, which impacts their Fermi surfaces and transport properties. Such 2DEGs, formed at transition metal oxide surfaces or interfaces, can also undergo surface phase transitions leading to polar metals that exhibit electronic nematicity. Motivated by experiments on such systems, we theoretically study magnetotransport in t2g orbital systems, using Hamiltonians that include atomic spin-orbit coupling and broken inversion symmetry, for both square symmetry (001) and hexagonal symmetry (111) 2DEGs. Using a numerical solution to the full multiband matrix-Boltzmann equation, together with insights gleaned from the impurity scattering overlap matrix, we explore the anisotropic magnetoresistance (AMR) in the presence of impurities which favor small momentum scattering. We find that transport in the (001) 2DEG is dominated by a single pair of bands, weakly coupled by impurity scattering, one of which has a larger Fermi velocity while the other provides an efficient current-relaxation mechanism. This leads to strong angle-dependent current damping and a large AMR with many angular harmonics. In contrast, AMR in the (111) 2DEG typically features a single cos(2ϑ) harmonic, with the angle-averaged magnetoresistance being highly tunable by a symmetry-allowed trigonal distortion. We also explore how the (111) 2DEG Fermi sufaces are impacted by electronic nematicity via a surface phase transition into a 2D polar metal for which we discuss a Landau theory, and we show that this leads to distinct symmetry components and higher angular harmonics in the AMR. Our results are in qualitative agreement with experiments from various groups for 2DEGs at the SrTiO3 surface and the LaAlO3-SrTiO3 interface.

show abstract

Two-dimensional superconductivity at the (111) LaAlO3/SrTiO3 interface

Cited by 62 publications

References 33 publications

Angle dependence of Hc2 with a crossover between the orbital and paramagnetic limits

Angle dependence of Hc2 with a crossover between the orbital and paramagnetic limits

Magnetic and Nematic Orders of the Two-Dimensional Electron Gas at Oxide (111) Surfaces and Interfaces

Anisotropic magnetoresistance in multiband systems: Two-dimensional electron gases and polar metals at oxide interfaces

Contact Info

Product

Resources

About