The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Aurore Finco - One of the best experts on this subject based on the ideXlab platform.
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Electric and antiferromagnetic chiral textures at multiferroic domain walls
Nature Materials, 2020Co-Authors: J. -y. Chauleau, T. Chirac, S. Fusil, V. Garcia, W. Akhtar, J. Tranchida, P. Thibaudeau, Isabell Gross, C. Blouzon, Aurore FincoAbstract:Chirality, a Foundational Concept throughout science, may arise at ferromagnetic domain walls 1 22 and in related objects such as skyrmions 2. However, chiral textures should also exist in other types 23 of ferroics such as antiferromagnets for which theory predicts that they should move faster for 24 lower power 3 , and ferroelectrics where they should be extremely small and possess unusual 25 topologies 4,5. Here we report the concomitant observation of antiferromagnetic and electric chiral 26 textures at domain walls in the room-temperature ferroelectric antiferromagnet BiFeO 3. 27 Combining reciprocal and real-space characterization techniques, we reveal the presence of 28 periodic chiral antiferromagnetic objects along the domain walls as well as a priori energetically 29 unfavorable chiral ferroelectric domain walls. We discuss the mechanisms underlying their 30 formation and their relevance for electrically controlled topological oxide electronics and 31 spintronics. 32 33 Metallic ferromagnets have been the elemental bricks of spintronics for the last three decades and 34 continue to hold promises on the basis of non-collinear chiral spin textures such as skyrmions. These 35 topologically protected objects are envisioned to be the future of magnetic data storage thanks to 36 their specific stability, dynamics, and scalability 2. In parallel, antiferromagnets (AFs) are emerging as a 37 new paradigm for spintronics 6. They are intrinsically stable (being insensitive to spurious magnetic 38 fields), scalable (no cross talk between neighbouring memory cells), and fast (switching frequencies 39 in the THz regime). The opportunity of gathering the best of these two worlds and realize 40 "antiferromagnetic skyrmions" is then tremendously appealing but faces at least two major 41 challenges. The first one is to achieve antiferromagnetic chirality and the second one is to identify 42 appropriate control stimuli to create, annihilate and move these chiral objects. 43 On one hand, chirality may naturally emerge at domain walls. The antiferromagnetic domain wall 44 structure is a virtually uncharted territory but this is where translational symmetry is broken and spin 45 rotation favoured. On the other hand, AF manipulation is hampered by the intrinsic lack of net 46 magnetization, which prevents a straightforward magnetic actuation. This fundamental issue may be 47
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Electric and antiferromagnetic chiral textures at multiferroic domain walls
Nature Materials, 2020Co-Authors: J. -y. Chauleau, T. Chirac, S. Fusil, V. Garcia, W. Akhtar, J. Tranchida, P. Thibaudeau, Isabell Gross, C. Blouzon, Aurore FincoAbstract:Chirality, a Foundational Concept throughout science, may arise at ferromagnetic domain walls1 and in related objects such as skyrmions2. However, chiral textures should also exist in other types of ferroic materials, such as antiferromagnets, for which theory predicts that they should move faster for lower power3, and ferroelectrics, where they should be extremely small and possess unusual topologies4,5. Here, we report the concomitant observation of antiferromagnetic and electric chiral textures at domain walls in the room-temperature ferroelectric antiferromagnet BiFeO3. Combining reciprocal and real-space characterization techniques, we reveal the presence of periodic chiral antiferromagnetic objects along the domain walls as well as a priori energetically unfavourable chiral ferroelectric domain walls. We discuss the mechanisms underlying their formation and their relevance for electrically controlled topological oxide electronics and spintronics.
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Electric and antiferromagnetic chiral textures at multiferroic domain walls
Nature Materials, 2019Co-Authors: J. -y. Chauleau, T. Chirac, S. Fusil, V. Garcia, W. Akhtar, J. Tranchida, P. Thibaudeau, Isabell Gross, C. Blouzon, Aurore FincoAbstract:Chiral electric and magnetic structures are observed at domain walls in thin films of the room-temperature multiferroic BiFeO_3. Chirality, a Foundational Concept throughout science, may arise at ferromagnetic domain walls^ 1 and in related objects such as skyrmions^ 2 . However, chiral textures should also exist in other types of ferroic materials, such as antiferromagnets, for which theory predicts that they should move faster for lower power^ 3 , and ferroelectrics, where they should be extremely small and possess unusual topologies^ 4 , 5 . Here, we report the concomitant observation of antiferromagnetic and electric chiral textures at domain walls in the room-temperature ferroelectric antiferromagnet BiFeO_3. Combining reciprocal and real-space characterization techniques, we reveal the presence of periodic chiral antiferromagnetic objects along the domain walls as well as a priori energetically unfavourable chiral ferroelectric domain walls. We discuss the mechanisms underlying their formation and their relevance for electrically controlled topological oxide electronics and spintronics.
J. -y. Chauleau - One of the best experts on this subject based on the ideXlab platform.
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Electric and antiferromagnetic chiral textures at multiferroic domain walls
Nature Materials, 2020Co-Authors: J. -y. Chauleau, T. Chirac, S. Fusil, V. Garcia, W. Akhtar, J. Tranchida, P. Thibaudeau, Isabell Gross, C. Blouzon, Aurore FincoAbstract:Chirality, a Foundational Concept throughout science, may arise at ferromagnetic domain walls 1 22 and in related objects such as skyrmions 2. However, chiral textures should also exist in other types 23 of ferroics such as antiferromagnets for which theory predicts that they should move faster for 24 lower power 3 , and ferroelectrics where they should be extremely small and possess unusual 25 topologies 4,5. Here we report the concomitant observation of antiferromagnetic and electric chiral 26 textures at domain walls in the room-temperature ferroelectric antiferromagnet BiFeO 3. 27 Combining reciprocal and real-space characterization techniques, we reveal the presence of 28 periodic chiral antiferromagnetic objects along the domain walls as well as a priori energetically 29 unfavorable chiral ferroelectric domain walls. We discuss the mechanisms underlying their 30 formation and their relevance for electrically controlled topological oxide electronics and 31 spintronics. 32 33 Metallic ferromagnets have been the elemental bricks of spintronics for the last three decades and 34 continue to hold promises on the basis of non-collinear chiral spin textures such as skyrmions. These 35 topologically protected objects are envisioned to be the future of magnetic data storage thanks to 36 their specific stability, dynamics, and scalability 2. In parallel, antiferromagnets (AFs) are emerging as a 37 new paradigm for spintronics 6. They are intrinsically stable (being insensitive to spurious magnetic 38 fields), scalable (no cross talk between neighbouring memory cells), and fast (switching frequencies 39 in the THz regime). The opportunity of gathering the best of these two worlds and realize 40 "antiferromagnetic skyrmions" is then tremendously appealing but faces at least two major 41 challenges. The first one is to achieve antiferromagnetic chirality and the second one is to identify 42 appropriate control stimuli to create, annihilate and move these chiral objects. 43 On one hand, chirality may naturally emerge at domain walls. The antiferromagnetic domain wall 44 structure is a virtually uncharted territory but this is where translational symmetry is broken and spin 45 rotation favoured. On the other hand, AF manipulation is hampered by the intrinsic lack of net 46 magnetization, which prevents a straightforward magnetic actuation. This fundamental issue may be 47
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Electric and antiferromagnetic chiral textures at multiferroic domain walls
Nature Materials, 2020Co-Authors: J. -y. Chauleau, T. Chirac, S. Fusil, V. Garcia, W. Akhtar, J. Tranchida, P. Thibaudeau, Isabell Gross, C. Blouzon, Aurore FincoAbstract:Chirality, a Foundational Concept throughout science, may arise at ferromagnetic domain walls1 and in related objects such as skyrmions2. However, chiral textures should also exist in other types of ferroic materials, such as antiferromagnets, for which theory predicts that they should move faster for lower power3, and ferroelectrics, where they should be extremely small and possess unusual topologies4,5. Here, we report the concomitant observation of antiferromagnetic and electric chiral textures at domain walls in the room-temperature ferroelectric antiferromagnet BiFeO3. Combining reciprocal and real-space characterization techniques, we reveal the presence of periodic chiral antiferromagnetic objects along the domain walls as well as a priori energetically unfavourable chiral ferroelectric domain walls. We discuss the mechanisms underlying their formation and their relevance for electrically controlled topological oxide electronics and spintronics.
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Electric and antiferromagnetic chiral textures at multiferroic domain walls
Nature Materials, 2019Co-Authors: J. -y. Chauleau, T. Chirac, S. Fusil, V. Garcia, W. Akhtar, J. Tranchida, P. Thibaudeau, Isabell Gross, C. Blouzon, Aurore FincoAbstract:Chiral electric and magnetic structures are observed at domain walls in thin films of the room-temperature multiferroic BiFeO_3. Chirality, a Foundational Concept throughout science, may arise at ferromagnetic domain walls^ 1 and in related objects such as skyrmions^ 2 . However, chiral textures should also exist in other types of ferroic materials, such as antiferromagnets, for which theory predicts that they should move faster for lower power^ 3 , and ferroelectrics, where they should be extremely small and possess unusual topologies^ 4 , 5 . Here, we report the concomitant observation of antiferromagnetic and electric chiral textures at domain walls in the room-temperature ferroelectric antiferromagnet BiFeO_3. Combining reciprocal and real-space characterization techniques, we reveal the presence of periodic chiral antiferromagnetic objects along the domain walls as well as a priori energetically unfavourable chiral ferroelectric domain walls. We discuss the mechanisms underlying their formation and their relevance for electrically controlled topological oxide electronics and spintronics.
Gang Chen - One of the best experts on this subject based on the ideXlab platform.
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direct observation of large electron phonon interaction effect on phonon heat transport
Nature Communications, 2020Co-Authors: Jiawei Zhou, Hyun D Shin, Ke Chen, Bai Song, R A Duncan, A A Maznev, Keith A Nelson, Gang ChenAbstract:As a Foundational Concept in many-body physics, electron-phonon interaction is essential to understanding and manipulating charge and energy flow in various electronic, photonic, and energy conversion devices. While much progress has been made in uncovering how phonons affect electron dynamics, it remains a challenge to directly observe the impact of electrons on phonon transport, especially at environmental temperatures. Here, we probe the effect of charge carriers on phonon heat transport at room temperature, using a modified transient thermal grating technique. By optically exciting electron-hole pairs in a crystalline silicon membrane, we single out the effect of the phonon-carrier interaction. The enhanced phonon scattering by photoexcited free carriers results in a substantial reduction in thermal conductivity on a nanosecond timescale. Our study provides direct experimental evidence of the elusive role of electron-phonon interaction in phonon heat transport, which is important for understanding heat conduction in doped semiconductors. We also highlight the possibility of using light to dynamically control thermal transport via electron-phonon coupling.
Tetsuo Taka - One of the best experts on this subject based on the ideXlab platform.
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instinct as a Foundational Concept in adam smithʼs social theory
The History of Economic Thought, 2012Co-Authors: Tetsuo TakaAbstract:Adam Smith’s social theory analyzes and interprets both the unfolding and accumulative structures of human nature and society, while considering the foundation of human instinct. My reinterpretation makes it possible to achieve a coherent understanding of The Theory of Moral Sentiments and The Wealth of Nations, and to recognize the commonalities among Smith, Hume, and Darwin with respect to the viewpoint of evolutionary point of view. Smith’s Concept of “instinct” is distinctly biological; it differs obviously from Locke’s philosophical Concept and Hume’s psychological one. There is no doubt that Smith followed Locke and Hume in terms of his empirical understanding of human knowledge and ways of thinking; nonetheless, Smith remained convinced that animals had instincts-that is, they are born with innate programs. As shown in his detailed descriptions in “Of the External Senses”-including those of instinctual perception among the young of the partridge, the goose, and suckling animals, as well as worms that have no head but yet search for food-Smith came to this idea through elaborate direct observations and indirect observations via the work of Linnaeus. For Smith, the human species incorporates the instincts of self-interest (self-preservation) and mutual altruism (sociability, the propensity to exchange). This understanding is maintained without any change from that outlined in the “Letter to Authors of the Edinburgh Review” to that in the sixth edition of The Theory of Moral Sentiments. JEL classification numbers: B 10, B 31, B 41. * Part of this paper was read at First ESHET-JSHET Meeting, Sophia-Antipolis, 2006 and at Smith in Glasgow ’09, University of Glasgow, 2009. I would like to thank attendants of these meetings and two anonymous referees of this journal for their helpful comments. Any remaining errors are mines alone. The History of Economic Thought, Vol. 53, No. 2, 2011. C The Japanese Society for the History of Economic Though. The purpose of this essay is to suggest, on the basis of a precise examination of Adam Smith’s Conception of “instinct” -mainly scrutinized in his posthumous article “Of the External Senses” (ES hereafter) -that his social theory analyzes and interprets both the unfolding and accumulative structures of human nature and society, while considering the foundation of human instinct in a biological sense. This approach has, therefore, some bearing on recent works that focus on the importance of a biological ap-
Bai Song - One of the best experts on this subject based on the ideXlab platform.
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direct observation of large electron phonon interaction effect on phonon heat transport
Nature Communications, 2020Co-Authors: Jiawei Zhou, Hyun D Shin, Ke Chen, Bai Song, R A Duncan, A A Maznev, Keith A Nelson, Gang ChenAbstract:As a Foundational Concept in many-body physics, electron-phonon interaction is essential to understanding and manipulating charge and energy flow in various electronic, photonic, and energy conversion devices. While much progress has been made in uncovering how phonons affect electron dynamics, it remains a challenge to directly observe the impact of electrons on phonon transport, especially at environmental temperatures. Here, we probe the effect of charge carriers on phonon heat transport at room temperature, using a modified transient thermal grating technique. By optically exciting electron-hole pairs in a crystalline silicon membrane, we single out the effect of the phonon-carrier interaction. The enhanced phonon scattering by photoexcited free carriers results in a substantial reduction in thermal conductivity on a nanosecond timescale. Our study provides direct experimental evidence of the elusive role of electron-phonon interaction in phonon heat transport, which is important for understanding heat conduction in doped semiconductors. We also highlight the possibility of using light to dynamically control thermal transport via electron-phonon coupling.