Rare-Earth Metals

Rare-Earth Metal Quantum Science at UCI

The Eddleman Quantum Institute at UCI has a concentrated effort on the rare-earth metals, shown in yellow, due to the special properties of these elements.

The rare-earth metals have electronic, spectroscopic, and magnetic properties that make them unique among metals. As a result, they are critical components in an extensive array of practical applications including energy efficient lighting, superior fiber optics, highly emissive flat-panel displays, effective catalytic converters in automobiles, wind turbines, MRI, and any device that needs a magnet with a high power to weight ratio.

The special properties of the rare-earth metals also make them valuable in exploring the frontiers of quantum science. UCI has a focus of effort on these extraordinary metals with SEVEN research groups working with these elements.

Detailed descriptions of rare-earth research at UCI are given below.

Access to a rare-earth metal card game suitable for outreach to children as young as 5 is available here.

The Chernyshev group

The Chernyshev group focuses on theoretical studies of the rare-earth-based quantum magnets, in which strongly spin-orbit-coupled f-shells of the rare-earths facilitate anisotropic spin-spin interactions. Of special interest are the systems that combine the archetypal geometric frustration with strong anisotropy. The central objective is to advance understanding of the extensive family of quantum materials, which offer an unusually rich spectrum of opportunities for realizing unconventional ordered and exotic quantum-disordered phases.

Leading references:

“Disorder-Induced Mimicry of a Spin Liquid in YbMgGaO4,” Zhenyue Zhu, P. A. Maksimov, Steven R. White, and A. L. Chernyshev, Phys. Rev. Lett. 119, 157201 (2017). DOI: 10.1103/PhysRevLett.119.157201

“Topography of Spin Liquids on a Triangular Lattice,” Zhenyue Zhu, P. A. Maksimov, Steven R. White, and A. L. Chernyshev, Phys. Rev. Lett. 120, 207203 (2018). DOI: 10.1103/PhysRevLett.120.207203

“Anisotropic-exchange magnets on a triangular lattice: spin waves, accidental degeneracies, and dual spin liquids,” P. A. Maksimov, Zhenyue Zhu, Steven R. White, and A. L. Chernyshev, Phys. Rev. X 9, 021017 (2019). DOI: 10.1103/PhysRevX.9.021017

Sasha Chernyshev

The Evans Group

The Evans group synthesizes new classes of molecular rare-earth metal complexes with the goal of finding new properties and new opportunities in quantum science. The group has made new classes of single-molecule magnets as well as a new type of molecular qubit. The group has found new oxidation states for the rare-earth metals that have led to compounds with the highest magnetic moment known for a monometallic complex. The Evans group also collaborates with the Ho group to investigate magnetic entanglement of S = 1 rare-earth metal complexes with nickelocene, (C5H5)2Ni.

  • Glovebox for Synthetic Rare-Earth Metal Chemistry in the Evans Laboratory.

  • Sample doser for Ho instrument containing uranocene loaded in Evans glovebox.

    Leading references:

    “An N23– Radical-Bridged Terbium Complex Exhibiting Magnetic Hysteresis at 14 K” Jeffrey D. Rinehart, Ming Fang, William J. Evans, and Jeffrey R. Long, Journal of the American Chemical Society 2011, 133, 14236-14239. DOI: 10.1021/ja206286h

    “Record High Single-Ion Magnetic Moments through 4fn5d1 Electron Configurations in the Divalent Lanthanide Complexes [(C5H4SiMe3)3Ln] “Katie R. Meihaus, Megan E. Fieser, Jordan F. Corbey, William J. Evans, and Jeffrey R. Long, Journal of the American Chemical Society 2015, 137, 9855-9860. DOI: 10.1021/jacs.5b03710

    “Engineering electronic structure to prolong relaxation times in molecular qubits by minimising orbital angular momentum” Ana-Maria Ariciu, David H. Woen, Daniel N. Huh, Lydia Nodarki, Andreas K. Kostopoulos, Conrad A. P. Goodwin, Nicholas F. Chilton, Eric J. L. McInnes, Richard E. P. Winpenny, William J. Evans, and Floriana Tuna Nature Communications 2019, 10, 1-8. DOI: 10.1038/s41467-019-11309-3

    William J. Evans

    The Furche group

    The Furche research group’s research interests span quantum chemistry from formal electronic structure theory through software development to applications together with experimental groups. Recent directions include random phase approximation methods, nonadiabatic molecular dynamics, and properties of rare-earth and actinide compounds with unconventional electronic structure. Filipp Furche is a core contributor and co-founder of the Turbomole project. The group has an extensive collaboration with the Evans group on rare-earth metal compounds that has led to over 35 joint

    Leading references:

    “Synthesis of Ln(II)-in-Cryptand Complexes by Chemical Reduction of Ln(III)-in-Cryptand Precursors: Isolation of a Nd(II)-in-Cryptand Complex” Daniel N. Huh, Sierra R. Ciccone, Samuel Bekoe, Saswata Roy, Joseph W. Ziller, Filipp Furche, and William J. Evans Angewandte Chemie 2020, 137, 16275-16280. DOI:         10.1002/ange.202006393.         Angewandte Chemie, International Edition in English 2020, 59, 2-8. DOI: 10.1002/anie.202006393

    “Structural, Spectroscopic, and Theoretical Comparison of Traditional vs. Recently Discovered Ln2+ Ions in the [K(2.2.2-cryptand)][(C5H4SiMe3)3Ln] Complexes: The Variable Nature of Dy2+ and Nd2+     Megan E. Fieser, Matthew R. MacDonald, Brandon T. Krull, Jefferson E. Bates, Joseph W. Ziller, Filipp Furche, and William J. Evans Journal of the American Chemical Society 2015, 137, 369–382. DOI:1021/ja510831n

    “Isolation of Dysprosium and Yttrium Complexes of a Three-Electron Reduction Product in the Activation of Dinitrogen, the (N2)3- Radical” William J. Evans, Ming Fang, Gaël Zucchi, Filipp Furche, Joseph W. Ziller, Ryan M. Hoekstra, and Jeffrey I. Zink, Journal of American Chemical Society 2009, 131, 11195-11202.   DOI: 10.1021/ja9036753

    S. G. Balasubramani, G. P. Chen, S. Coriani, M. Diedenhofen, M. S. Frank, Y. J. Franzke, F. Furche, R. Grotjahn, M. E. Harding, C. Hättig, A. Hellweg, B. Helmich-Paris, C. Holzer, U. Huniar, M. Kaupp, A. M. Khah, S. K. Khani, T. Müller, F. Mack, B. Nguyen, S. M. Parker, E. Perlt, D. Rappoport, K. Reiter, S. Roy, M. Rückert, G. A. Schmitz, M. Sierka, E. Tapavicza, D. P. Tew, C. van Wüllen, V. K. Voora, F. Weigend, A. Wodyński, and J. M. Yu: “TURBOMOLE: Modular program suite for ab initio quantum-chemical and condensed-matter simulations” J. Chem. Phys. ESS2020 (2020), 184107. doi: 10.1063/5.0004635.

    The Ho group

    The Ho group develops novel quantum sensors based on a single magnetic molecule attached to the tip of a scanning tunneling microscope (STM) to achieve atomic scale spatial resolution in magnetic sensing. By combining a femtosecond or a cw THz laser with the STM, ultrahigh energy and temporal resolutions are achieved in addition to the spatial resolution. These unique capabilities form the basis for a collaborative study with Bill Evans and Ruqian Wu on single organometallic molecules containing rare earth and actinide atoms such as uranocene [(C5H5)2U] and endohedral fullerenes (Tb3N@C80).

    • Single Molecule Imaging Apparatus in the Wilson Ho Lab

      Leading references:

      Gregory Czap, Peter J. Wagner, Jie Li, Feng Xue, Jiang Yao, R. Wu, and W. Ho, “Detection of spin-vibration states in single magnetic molecules”, Phys. Rev. Lett, 123, 106803 (2019).

      Gregory Czap, Peter J. Wagner, Feng Xue, Lei Gu, Jie Li, Jiang Yao, Ruqian Wu, and W. Ho, “Probing and imaging spin interactions with a magnetic single-molecule sensor”, Science, 364, 670 (2019).

      The Krivorotov group

      The Krivorotov group studies relativistic quantum phenomena of spin-orbit torques in ferro- and ferromagnetic rare earth oxides such as Y3Fe5O12 (yttrium iron garnet or YIG) and LaxSr1-xMnO3 (LSMO), as well as Bose-Einstein condensation of magnons in these materials.

      • Cryostation in the Krivorotov Laboratory
      • Ion Mill in the Krivorotov Laboratory
      • Probe Station in the Krivorotov Laboratory

        Leading references:

        Chris Safranski, Igor Barsukov, Han Kyu Lee, Tobias Schneider, A.A. Jara, Andrew Smith, Houchen Chang, Kilian Lenz, Juergen Lindner, Yaroslav Tserkovnyak, Mingzhong Wu, I.N. Krivorotov, “Spin caloritronic nano-oscillator”, Nat. Commun. 8, 117 (2017).

        M. Evelt, C. Safranski, Mohammed Aldosary, V.E. Demidov, I. Barsukov, A.P. Nosov, A.B. Rinkevich, K. Sobotkiewich, Xiaoqin Li, Jing Shi, I.N. Krivorotov, S.O. Demokritov, “Spin Hall-induced auto-oscillations in ultrathin YIG grown on Pt”, Sci. Rep. 8, 1269 (2018).

        Han Kyu Lee, I. Barsukov, A.G. Swartz, B. Kim, L. Yang, H.Y. Hwang, I.N. Krivorotov, “Magnetic anisotropy, damping, and interfacial spin transport in Pt/LSMO bilayers”, AIP Adv. 6, 055212 (2016).

        Aryan Navabi, Yuxiang Liu, Pramey Upadhyaya, Koichi Murata, Farbod Ebrahimi, Guoqiang Yu, Bo Ma, Yiheng Rao, Mohsen Yazdani, Mohammad Montazeri, Lei Pan, Ilya N. Krivorotov, Igor Barsukov, Qinghui Yang, Pedram Khalili Amiri, Yaroslav Tserkovnyak, Kang L. Wang, “Control of spin-wave damping in YIG using spin currents from topological insulators”, Phys. Rev. Applied 11, 034046 (2019).

        Ilya Krivorotov

        The Wu group

        The Wu group studies topological properties of SmB6 surface as well as rare earth and actinide atoms in oxide lattices for use as qubits. Theoretical analyses for the possibility of making exceedingly long coherence time of qubits with spin-vibration couplings was recently done. The Wu group is also in collaboration with the Ho and Evans groups in developing magnetic molecules for quantum computing, starting from (C5H5)2Ni and (C5H5)2Co.

        Leading references:

        Lei Gu, and Ruqian Wu, “Origins of slow magnetic relaxation in single-molecule magnets”, Phys. Rev. Lett, 125, 117203 (2020).

        Jie Li, Lei Gu, and Ruqian Wu, “Stable giant magnetic anisotropy energy and long coherence time of uranium adatoms on defect aluminum oxide”, Phys. Rev. B, 102, 054406 (2020).

        Gregory Czap, Peter J. Wagner, Jie Li, Feng Xue, Jiang Yao, R. Wu, and W. Ho, “Detection of spin-vibration states in single magnetic molecules”, Phys. Rev. Lett, 123, 106803 (2019).

        Gregory Czap, Peter J. Wagner, Feng Xue, Lei Gu, Jie Li, Jiang Yao, Ruqian Wu, and W. Ho, “Probing and imaging spin interactions with a magnetic single-molecule sensor”, Science, 364, 670 (2019).

        Tao Liu, Yufan Li, Lei Gu, Junjia Ding, Houchen Chang, P. A. Praveen Janantha, Boris Kalinikos, Valentyn Novosad, Axel Hoffmann, Ruqian Wu, C. L. Chien, and Mingzhong Wu, “Nontrivial nature and penetration depth of topological surface states in SmB6 thin films”, Phys. Rev. Lett. 120, 207206 (2018).

        The Xia group

        The Xia group has performed quantum transport and magnetic studies on the topological Kondo insulator SmB6 at milli-Kelvin ultra-low temperature to elucidate the origin of the intricate quantum oscillation in its surface state. And by utilizing the special mixed-valence properties of samarium in SmB6, they have successfully used strain to suppress the quantum fluctuations between the different valence states and stabilize the topological surface state to an unprecedented temperature of 240 Kelvin. This is important towards ambient temperature operation of a SmB6 radio frequency oscillator device that the group developed in 2016.

        Leading references:

        “Radio Frequency Tunable Oscillator Device Based on SmB6 Micro-crystal”, A. Stern, D.K. Efimkin, V. Galitski, Z. Fisk and J. Xia, Phys. Rev. Lett. 116(16), 166603, (2016).

        “Surface-dominated conduction up to 240 K in the Kondo insulator SmB6 under strain”, A. Stern, M. Dzero, V. M. Galitski, Z. Fisk, J. Xia, Nature Materials, 16, 708-711 (2017).

        “Direct observation of surface-state thermal oscillations in SmB6 oscillators”, Brian Casas, Alex Stern, Dmitry K. Efimkin, Zachary Fisk, and Jing Xia, Phys. Rev. B 97, 035121 (2018).

        “Quantum Oscillations in Flux-Grown SmB6 with Embedded Aluminum”, S. M. Thomas, Xiaxin Ding, F. Ronning, V. Zapf, J. D. Thompson, Z. Fisk, J. Xia, and P. F. S. Rosa, Phys. Rev. Lett. , 122, 166401 (2019).


        Professor William J. Evans, Director

        Please email Ms. Jenise Shourds

        164 Rowland Hall
        University of California, Irvine
        Irvine, CA 92697-4675