Article
Physics, Multidisciplinary
Matthew Rogers, Alistair Walton, Machiel G. Flokstra, Fatma Al Ma'Mari, Rhea Stewart, Stephen L. Lee, Thomas Prokscha, Andrew J. Caruana, Christian J. Kinane, Sean Langridge, Harry Bradshaw, Timothy Moorsom, Mannan Ali, Gavin Burnell, Bryan J. Hickey, Oscar Cespedes
Summary: The combination of magnetic molecules with a metallic substrate allows for the manipulation of molecular spin properties and potential application in low-power information storage devices. Research demonstrates the feasibility of achieving spin-ordering and superconducting properties at the metallo-molecular interface, enabling lower energy spin transfer and magnetic switching in quantum computing and information storage. The results showcase the potential of metallo-molecular interfaces for singlet to triplet Cooper pair conversion, offering a new capability for generating and controlling the diffusion of spin polarized dissipationless currents.
COMMUNICATIONS PHYSICS
(2021)
Article
Physics, Multidisciplinary
Lina G. Johnsen, Haakon T. Simensen, Arne Brataas, Jacob Linder
Summary: At the interface between a ferromagnetic insulator and a superconductor, a coupling between the spins of the two materials results in the induction of a magnon spin current in the adjacent ferromagnetic insulator by a supercurrent carried by triplet Cooper pairs. This effect is dominated by Cooper pairs polarized in the same direction as the ferromagnetic insulator, showing that charge and spin supercurrents produce similar results in this system. This study demonstrates a method of converting Cooper pair supercurrents into magnon spin currents.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Qingzhen Wang, Sebastiaan L. D. ten Haaf, Ivan Kulesh, Di Xiao, Candice Thomas, Michael J. Manfra, Srijit Goswami
Summary: By coupling two quantum dots via a superconductor-semiconductor hybrid region, the authors achieve efficient splitting of Cooper pairs and measure large triplet correlations using a perpendicular magnetic field. This is the first demonstration of Cooper pair splitting in a semiconductor two-dimensional electron gas (2DEG). The exceptionally large spin-orbit interaction in their 2DEGs allows for a strong triplet component in the splitting process. This demonstration provides a credible route for studying on-chip entanglement and topological superconductivity.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Michael E. Berkowitz, Brian S. Y. Kim, Guangxin Ni, Alexander S. McLeod, Chiu Fan Bowen Lo, Zhiyuan Sun, Genda Gu, Kenji Watanabe, Takashi Taniguchi, Andrew J. Millis, James C. Hone, Michael M. Fogler, Richard D. Averitt, D. N. Basov
Summary: The study reveals that weak HCP features in the near-field can be significantly enhanced by coupling graphene SPP and HCP in layered graphene/hBN/Bi-2212 heterostructures. This enhancement arises from the multilayered structures acting as plasmonic cavities, altering collective modes of the layered superconductor.
Article
Physics, Multidisciplinary
Yuri Fukaya, Tatsuki Hashimoto, Masatoshi Sato, Yukio Tanaka, Keiji Yada
Summary: We investigated the spin susceptibility of orbital-singlet pairings in a three-dimensional three-orbital model of superconducting Sr2RuO4. The spin susceptibility decreases with decreasing temperature, regardless of the direction of the applied magnetic fields. However, the spin susceptibility for certain pairings is reduced by around 5-10% along the z (x) axis due to the alignment of the pseudospin-triplet d-vector in the band basis. The temperature dependence of the spin susceptibility measured by nuclear magnetic resonance experiments can be used to determine the symmetry of the pseudospin structure of the Cooper pair, providing guidance for determining the pairing symmetry of Sr2RuO4.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Fredrik Brange, Kacper Prech, Christian Flindt
Summary: This paper proposes a dynamic Cooper pair splitter that generates noiseless and regular flow of spin-entangled electrons by adjusting the energy levels of quantum dots and coupling them to a superconductor. The optimal operating conditions are identified to ensure exactly one Cooper pair split per external drive period, leading to noiseless flow of entangled electrons. Characterization of the regularity of the Cooper pair splitter is performed in the time domain through analysis of g(2) function of output currents and distribution of waiting times between split Cooper pairs.
PHYSICAL REVIEW LETTERS
(2021)
Article
Multidisciplinary Sciences
Victor G. Yarzhemsky
Summary: Experimental data on Sr2RuO4 and Fe-pnictide superconductors show potential presence of odd and even Cooper pairs, suggesting the need for further investigation on their superconducting properties.
Article
Materials Science, Multidisciplinary
Feng-Rong Shi
Summary: This paper investigates the quantum transport properties in a double-quantum-dot circuit with two laterally-coupled superconductors. The results show that the characteristics of electron tunneling and local and crossed Andreev reflections vary with the adjustment of the phase difference between the superconductors. Moreover, appropriate phase differences can enhance crossed Andreev reflection and suppress local Andreev reflection and electron tunneling.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
D. C. Cavanagh, Daniel F. Agterberg, P. M. R. Brydon
Summary: We investigate the effect of symmetry-breaking perturbations on superconductivity in multiorbital materials, focusing on the influence of an external magnetic field. We introduce the field-fitness function to characterize the disruption of pair formation due to the perturbation. In even-parity superconductors, the field-fitness function for an external magnetic field is unity, indicating that the paramagnetic response is determined solely by a generalized effective g-factor. For odd-parity superconductors, the interplay between the effective g-factor and the field-fitness function can result in counterintuitive outcomes. We demonstrate this phenomenon in the p-wave pairing of the effective j=32 electronic states in the Luttinger-Kohn model.
Article
Physics, Multidisciplinary
P. Pandey, R. Danneau, D. Beckmann
Summary: The experimental study of a Cooper pair splitter based on ballistic graphene multi-terminal junctions showed clear signatures of Cooper pair splitting in both local and nonlocal electronic transport measurements. The experimental data can be well described by the beam splitter model, opening up possibilities for designing new entangled state detection experiments using ballistic Cooper pair splitters.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Siddhartha Patra, Siddhartha Lal
Summary: This study presents a microscopic derivation of the Cooper-pair insulator (CPI) and reveals its topologically ordered nature through a generalized model of electrons with attractive interactions. The CPI effective Hamiltonian displays characteristics of topological order, with a fourfold degeneracy in the ground-state manifold. The long-ranged many-particle entanglement content of the CPI ground state is shown to be driven by interhelicity two-particle scattering processes.
Article
Multidisciplinary Sciences
Brandon K. Rugg, Kori E. Smyser, Brian Fluegel, Christopher H. Chang, Karl J. Thorley, Sean Parkin, John E. Anthony, Joel D. Eaves, Justin C. Johnson
Summary: The photo-driven process of singlet fission can generate coupled triplet pairs with intriguing properties. Among the sublevels, the quintet is particularly interesting for quantum information. Previous theoretical work has shown that this sublevel can be selectively populated under certain conditions.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Physics, Multidisciplinary
Alexander Wietek
Summary: This study investigates the properties of the superconducting ground state in a two-dimensional model with striped superconductivity, and finds that fragmented condensates occur in the presence of charge density modulations. These fragmented condensates, located on the stripes, hybridize to form an extended macroscopic wave function.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Stefano Trivini, Jon Ortuzar, Katerina Vaxevani, Jingchen Li, F. Sebastian Bergeret, Miguel A. Cazalilla, Jose Ignacio Pascual
Summary: We demonstrate that a single tunneling electron can induce pair breaking excitations in a proximitized gold film containing magnetic impurities. By combining scanning tunneling spectroscopy with theoretical modeling, we map the excitation spectrum of a Fe-porphyrin molecule on the Au/Vo100 thorn proximitized surface to a manifold of entangled Yu-Shiba-Rusinov and spin excitations. Pair excitations only emerge in the tunneling spectra as peaks outside the spectral gap in the strong coupling regime, where a bound quasiparticle in the ground state ensures the even fermion parity of the excitation. Our results unravel the quantum nature of magnetic impurities on superconductors and demonstrate that pair excitations unequivocally reveal the parity of the ground state.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Z. B. Tan, A. Laitinen, N. S. Kirsanov, A. Galda, V. M. Vinokur, M. Haque, A. Savin, D. S. Golubev, G. B. Lesovik, P. J. Hakonen
Summary: The non-local Seebeck effect has been observed in a graphene-based Cooper pair splitting device, offering a potential tool for producing entangled electrons. This phenomenon arises from the interplay of non-local Cooper pair splitting and elastic co-tunneling in normal metal-superconductor-normal metal structures.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Georgios Varnavides, Yaxian Wang, Philip J. W. Moll, Polina Anikeeva, Prineha Narang
Summary: A theoretical framework for electron transport in single-crystal delafossite metals is presented using a combination of first-principles calculations and numerical modeling. The study investigates different electron and phonon scattering mechanisms and establishes a hierarchy of mean free path for quasiparticles at different temperatures. The anisotropic Fermi surface is explicitly treated to obtain experimentally-accessible transport observables, bridging the diffusive, ballistic, and hydrodynamic transport regime limits. The research provides insights into microscopic interaction mechanisms on open hexagonal Fermi surfaces and their connection to macroscopic electron transport in finite-size channels.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Multidisciplinary
Nicholas R. Poniatowski, Jonathan B. Curtis, Amir Yacoby, Prineha Narang
Summary: This study investigates two unique collective modes of order parameters in time-reversal symmetry breaking superconductors and proposes using them to identify these exotic states.
COMMUNICATIONS PHYSICS
(2022)
Article
Physics, Applied
Derek S. Wang, David D. Dai, Prineha Narang
Summary: This article describes how a ladder emitter can be used to implement a tunable quantum logic gate on photonic qubits encoded in the frequency basis. By controlling the interactions between different photons, arbitrary phase control operations can be achieved. This gate is deterministic, does not require active control, and only needs a single ladder emitter, allowing for low-footprint and more efficient decomposition of quantum circuits.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Zhigang Song, Yu Wang, Haimei Zheng, Prineha Narang, Lin-Wang Wang
Summary: Recently, there has been significant interest in non-vdW moire superlattices. In this study, we theoretically predict unusual properties based on the chemical bonding between twisted PbS nanosheets. Experimental observations confirm the accessibility and stability of these non-vdW moire superlattices.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Multidisciplinary Sciences
Christian Schaefer, Johannes Flick, Enrico Ronca, Prineha Narang, Angel Rubio
Summary: The study reveals the microscopic mechanism behind the reduced reaction rate observed in cavity-induced resonant vibrational strong light-matter coupling using quantum-electrodynamical density-functional theory. The cavity mode acts as a mediator between different vibrational modes, redistributing vibrational energy and ultimately inhibiting the reaction.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
A. S. Disa, J. Curtis, M. Fechner, A. Liu, A. von Hoegen, M. Foerst, T. F. Nova, P. Narang, A. Maljuk, A. V. Boris, B. Keimer, A. Cavalleri
Summary: Lattice manipulation through optical methods can enhance and stabilize high-temperature ferromagnetism, expanding the potential applications of YTiO3.
Review
Nanoscience & Nanotechnology
Georgios Varnavides, Amir Yacoby, Claudia Felser, Prineha Narang
Summary: As high-quality single-crystal materials used in electronic devices reach smaller scales, charge-transport phenomena lead to inhomogeneous spatial signatures with significant effects on material properties. These signatures, including spatially varying dissipation and interface resistance, are crucial for device control. This Review examines the inhomogeneous charge flow signatures in conductors, focusing on electron hydrodynamics, where electrons exhibit strong interactions and flow collectively like fluids. Recent experimental advances and theoretical frameworks are discussed, along with new charge-transport phenomena introduced by crystal symmetry in materials.
NATURE REVIEWS MATERIALS
(2023)
Article
Multidisciplinary Sciences
Bohan Li, Aritra Das, Spyros Tserkis, Prineha Narang, Ping Koy Lam, Syed M. Assad
Summary: The maximum entanglement achievable through passive transformations by continuous-variable states is called the entanglement potential. Recent research indicates that the entanglement potential can be upper-bounded by a simple function of squeezing of formation. Certain classes of two-mode Gaussian states can saturate this bound, but it remains an open problem for the general case. In this study, a larger class of states is introduced that is proven to saturate the bound, and it is conjectured that all two-mode Gaussian states can be passively transformed into this class, thereby equating entanglement potential with squeezing of formation. An explicit algorithm for the passive transformations is provided, and extensive numerical testing is performed to support this claim, aiming to unify the resource theories of two characteristic quantum properties of continuous-variable systems.
SCIENTIFIC REPORTS
(2023)
Article
Optics
Anthony W. Schlimgen, Kade Head-Marsden, LeeAnn M. Sager-Smith, Prineha Narang, David A. Mazziotti
Summary: This paper presents a dilation-based algorithm to simulate nonunitary operations on quantum computing devices. The algorithm decomposes any quantum operator into two unitary operators and a nonunitary operator using singular value decomposition (SVD), and implements the nonunitary operator using a diagonal unitary operator in a dilated space. Despite increasing the number of qubits, the algorithm limits the operations required in the dilated space to a diagonal unitary operator with known circuit decompositions.
Article
Materials Science, Multidisciplinary
Jonathan B. Curtis, Nicholas R. Poniatowski, Amir Yacoby, Prineha Narang
Summary: This study presents a platform for spectroscopic probing of unconventional superconductivity in thin-layer materials through the proximity effect. The observation of changes in collective modes and condensation provides insights into the pairing interactions and superconducting properties of the materials.
Article
Physics, Multidisciplinary
Anthony W. Schlimgen, Kade Head-Marsden, LeeAnn M. Sager, Prineha Narang, David A. Mazziotti
Summary: Accurate simulation of quantum systems' time evolution under the influence of an environment is crucial for predicting phenomena in chemistry, condensed-matter physics, and materials sciences. This study presents a quantum algorithm that utilizes a decomposition of nonunitary operators to model dynamic processes, demonstrating the potential of predicting population dynamics using quantum devices in important systems such as molecular energy transport and quantum optics.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Quantum Science & Technology
Zixuan Hu, Kade Head-Marsden, David A. Mazziotti, Prineha Narang, Sabre Kais
Summary: This paper introduces the research on using quantum algorithms to simulate complex physical processes and demonstrates the simulation of the dynamics of the FMO complex using a quantum algorithm. The study shows that quantum methods have a query complexity advantage in addressing open quantum dynamics.
Article
Physics, Multidisciplinary
Dominik M. Juraschek, Tomas Neuman, Prineha Narang
Summary: This paper presents a mechanism by which optically driven chiral phonon modes in rare-earth trihalides generate giant effective magnetic fields acting on the paramagnetic 4f spins. Using CeCl3 as an example, the coherent phonon dynamics in response to an ultrashort terahertz pulse are calculated using a combination of phenomenological modeling and first-principles calculations. It is found that effective magnetic fields of over 100 T can potentially be generated, polarizing the spins for experimentally accessible pulse energies.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Ian MacCormack, Conor Delaney, Alexey Galda, Nidhi Aggarwal, Prineha Narang
Summary: Neural-network-based algorithms have been widely studied for their ability in learning complex patterns and classifying quantum and classical data sets. This paper introduces a new algorithm, branching quantum convolutional neural network (bQCNN), which leverages a branching structure and midcircuit measurement results to enhance expressibility. Experimental results show that bQCNN outperforms ordinary QCNN in specific tasks. This algorithm has potential applications in noisy intermediate-scale quantum devices.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Jonathan B. Curtis, Andrey Grankin, Nicholas R. Poniatowski, Victor M. Galitski, Prineha Narang, Eugene Demler
Summary: Controlling quantum matter with cavities offers new ways to study and manipulate many-body systems, particularly in unconventional or high-Tc systems. This paper proposes a scheme for coupling terahertz resonators to antiferromagnetic fluctuations in cuprate families to enhance superconductivity, and explores the underlying coupling mechanisms.
PHYSICAL REVIEW RESEARCH
(2022)
