Superconductor-Metal Quantum Transition at the EuO/KTaO<sub>3</sub> Interface*

Ma, Yang; Niu, Jiasen; Xing, Wenyu; Yao, Yuan; Cai, Ranran; Sun, Jinhe; Xie, Xiaoming; Lin, Xi; Han, Wei

doi:10.1088/0256-307x/37/11/117401

Cited by 23 publications

(21 citation statements)

References 32 publications

(69 reference statements)

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“…The electron mo- bility for Samples #1 and #2 is thus 193.6 cm 2 V −1 s −1 and 159.7 cm 2 V −1 s −1 . These results are highly reproducible and reasonably consistent with previous electrical transport studies on EuO/KTaO 3 [11,12] and LaAlO 3 /KTaO 3 [11,13]. Remarkably, as the temperature is further decreased, the resistance R s undergoes a narrow and sharp transition with a transition width of less than 0.5 K to a zero-resistance state, signaling the appearance of superconductivity at the interface of YAlO 3 /KTaO 3 .…”

Section: (D)supporting

confidence: 89%

“…Very recently, unexpected crystalline-orientation dependent superconductivity has been experimentally observed at the interface between EuO (or LaAlO 3 ) and KTaO 3 (T c ∼ 2 K) [11][12][13], which shows near two orders of magnitude enhancement in T c compared to its threedimensional counterpart [14]. This findings suggest that superconductivity at KTaO 3 interfaces is an intrinsic interface property.…”

mentioning

confidence: 99%

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Spontaneous rotational symmetry breaking in KTaO$_3$ interface superconductors

Zhang¹,

Wang²,

Wang³

et al. 2021

Preprint

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We report the observation of spontaneous rotational symmetry breaking of the superconductivity at the interface of YAlO3/KTaO3 with a superconducting transition temperature of 1.86 K. Both the magnetoresistance and upper critical field in an in-plane field manifest striking asymmetric twofold oscillations deep inside the superconducting state, whereas the anisotropy vanishes in the normal state, demonstrating that this is an intrinsic property of the superconducting phase. We attribute this behavior to the mixed-parity superconducting state, which is an admixture of s-wave and p-wave pairing components induced by strong spin-orbit coupling. Our work demonstrates the unconventional nature of the pairing interaction in the KTaO3 interface superconductor, and provides a new platform to clarify a delicate interplay of electron correlation and spin-orbit coupling.

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Section: (D)supporting

confidence: 89%

mentioning

confidence: 99%

Spontaneous rotational symmetry breaking in KTaO$_3$ interface superconductors

Zhang¹,

Wang²,

Wang³

et al. 2021

Preprint

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“…While STO is the first found superconducting semiconductor known since 1964 ( 15 ), the first report of superconductivity in KTO was in 2011 ( 22 ), when a T c of ~50 mK was observed at KTO(001) surface gated with IL. After that, there was a decade of silence until the recent discovery on a family of KTO interfaces ( 12 – 14 , 19 , 20 ). Unusually, the superconductivity of these interfaces exhibits a strong dependence on the KTO surface planes: The (111) ( 12 ) and (110) ( 13 ) interfaces have an optimal T c of 2.2 and 0.9 K, respectively, a big leap from aforementioned 50 mK ( 22 ); in contrast, no superconductivity was detected at the (001) interface down to 25 mK ( 12 ).…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional superconductivity at the surfaces of KTaO ₃ gated with ionic liquid

Ren¹,

Li²,

Sun³

et al. 2022

Sci. Adv.

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The recent discovery of superconductivity at the interfaces between KTaO 3 and EuO (or LaAlO 3 ) gives birth to the second generation of oxide interface superconductors. This superconductivity exhibits a strong dependence on the surface plane of KTaO 3 , in contrast to the seminal LaAlO 3 /SrTiO 3 interface, and the superconducting transition temperature T c is enhanced by one order of magnitude. For understanding its nature, a crucial issue arises: Is the formation of oxide interfaces indispensable for the occurrence of superconductivity? Exploiting ionic liquid (IL) gating, we are successful in achieving superconductivity at KTaO 3 (111) and KTaO 3 (110) surfaces with T c up to 2.0 and 1.0 K, respectively. This oxide-IL interface superconductivity provides a clear evidence that the essential physics of KTaO 3 interface superconductivity lies in the KTaO 3 surfaces doped with electrons. Moreover, the controllability with IL technique paves the way for studying the intrinsic superconductivity in KTaO 3 .

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“…They observed quantum Griffith's singularity arose due to large rare superconducting regions in EuO–KTO (111) interface. [ 205 ]…”

Section: Low‐dimensional Electron Gas In Ktao3: Surfaces and Interfacesmentioning

confidence: 99%

KTaO₃—The New Kid on the Spintronics Block

Gupta¹,

Harsha²,

Kumari³

et al. 2022

Advanced Materials

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Long after the heady days of high‐temperature superconductivity, the oxides came back into the limelight in 2004 with the discovery of the 2D electron gas (2DEG) in SrTiO3 (STO) and several heterostructures based on it. Not only do these materials exhibit interesting physics, but they have also opened up new vistas in oxide electronics and spintronics. However, much of the attention has recently shifted to KTaO3 (KTO), a material with all the “good” properties of STO (simple cubic structure, high mobility, etc.) but with the additional advantage of a much larger spin‐orbit coupling. In this state‐of‐the‐art review of the fascinating world of KTO, it is attempted to cover the remarkable progress made, particularly in the last five years. Certain unsolved issues are also indicated, while suggesting future research directions as well as potential applications. The range of physical phenomena associated with the 2DEG trapped at the interfaces of KTO‐based heterostructures include spin polarization, superconductivity, quantum oscillations in the magnetoresistance, spin‐polarized electron transport, persistent photocurrent, Rashba effect, topological Hall effect, and inverse Edelstein Effect. It is aimed to discuss, on a single platform, the various fabrication techniques, the exciting physical properties and future application possibilities of this family of materials.

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Superconductor-Metal Quantum Transition at the EuO/KTaO₃ Interface*

Cited by 23 publications

References 32 publications

Spontaneous rotational symmetry breaking in KTaO$_3$ interface superconductors

Spontaneous rotational symmetry breaking in KTaO$_3$ interface superconductors

Two-dimensional superconductivity at the surfaces of KTaO ₃ gated with ionic liquid

KTaO₃—The New Kid on the Spintronics Block

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Superconductor-Metal Quantum Transition at the EuO/KTaO3 Interface*

Cited by 23 publications

References 32 publications

Spontaneous rotational symmetry breaking in KTaO$_3$ interface superconductors

Spontaneous rotational symmetry breaking in KTaO$_3$ interface superconductors

Two-dimensional superconductivity at the surfaces of KTaO 3 gated with ionic liquid

KTaO3—The New Kid on the Spintronics Block

Contact Info

Product

Resources

About

Superconductor-Metal Quantum Transition at the EuO/KTaO₃ Interface*

Two-dimensional superconductivity at the surfaces of KTaO ₃ gated with ionic liquid

KTaO₃—The New Kid on the Spintronics Block