Condensed Matter & Thermal Physics Group, MPA-10

MPA-10 in the news

ICAM workshop honors condensed matter physicist Joe D. Thompson

The Institute for Complex Adaptive Matter (ICAM)recently hosted “The Heavy Fermion Frontier: a Workshop in Honor of Joe D. Thompson’s 60th Birthday” in Santa Fe. The workshop, organized by MPA-10’s Zachary Fisk and MPA-DO’s John Sarrao, brought together heavy-fermion researchers from around the world to discuss the field’s current state and its future direction. A retrospective slide show was presented at the banquet highlighting Thompson’s accomplishments during the past 20 years and included numerous photos of Thompson’s former postdoctoral researchers, many who are now grey-haired Los Alamos managers. Thompson is a fellow of the American Physical Society, the American Association for the Advancement of Science, and Los Alamos National Laboratory. He is also a senior fellow of the Japan Physical Society. His research in condensed-matter physics has spanned problems posed by a spectrum of materials and is motivated primarily by interest in discovering and understanding exotic states produced by strong electronic correlations and the response of these states to high pressures.

December 2007

New MPA-10 research sheds light on underlying mechanisms of superconductivity

By hole-doping with cadmium, lead author and MPA-10 postdoctoral researcher Ricardo Urbano and coworkers can tune the ground state in heavy fermion superconductor CeCoIn₅ between superconductivity and antiferromagnetism. Urbano’s nuclear magnetic resonance data indicate that these two orders coexist microscopically, with the magnetism emerging locally in the vicinity of the Cd dopants in the form of antiferromagnetic droplets. The data suggest that the magnetism emerges locally in the vicinity of the Cd dopants in the form of antiferromagnetic droplets. This system offers a new way to investigate the dynamics of a quantum critical system and can shed light on the underlying mechanism of superconductivity. The work, “Interacting Antiferromagnetic Droplets in Quantum Critical CeCoIn₅,” by Urbano, Nicholas Curro, and Joe Thomspon, MPA-10; B.-L. Young, National Chiao Tung University, Taiwan; LD. Pham, University of California, Davis; and Z. Fisk, University of California, Irvine, appears in Physical Review Letters 99, 146402 (2007). Work at Los Alamos National Laboratory was funded by the Los Alamos National Laboratory Directed Research and Development program.

December 2007

Roman Movshovich selected as Laboratory Fellow

Roman Movshovich, MPA-10, has been named a Los Alamos National Laboratory Fellow, the Laboratory’s highest scientific recognition of outstanding achievement. Movshovich is being recognized for his important achievements in the field of correlated electron physics. Movshovich is an internationally recognized leader in low temperature physics whose scientific acumen and innovative thinking have led to significant discoveries and critical insight in elucidating the properties of strongly correlated electron and heavy fermion systems. He has published more than 100 papers that have been cumulatively cited more than 2,200 times. Movshovich, who earned his PhD in physics from Cornell University, joined the Laboratory as a Director’s Postdoctoral Fellow in 1992 and became a member of the technical staff in 1994. Previous honors include the California Institute of Technology Jack E. Froehlich Memorial Award (1982); Carnation-CIT Prize Scholarship (1982-1983); an AT&T Ph.D. Fellowship (1984-1988); a Los Alamos Achievement Award (1999); a Los Alamos Fellows Prize (2003); and a fellowship of the American Physical Society (2005). Movschovich’s primary research interests lie in areas of heavy-fermion materials, non-Fermi-liquids and quantum critical phenomena, frustrated magnets, unconventional superconductivity, and high temperature superconductivity. His current research is focused on CeIrIn₅ and CeCoIn₅, the ambient pressure heavy fermion superconductors discovered over the last several years.

November 2007

MPA-10 GRA nets best poster at GNEP review

MPA-10 Graduate Research Assistant Peter Hosemann received the best poster award presented at the recent Global Nuclear Energy Partnership program (GNEP) annual review in Phoenix. The poster, “Ion beam irradiation studies on materials” by Hosemann; Stuart Maloy, MST-8; Ning Li, MPA-10; Greg Swadener, MPA-CINT; D. Kiener, University of Leoben, Austria; G.S. Was, University of Michigan; M. Okuniewski, University of Illinois, Champaign-Urbana, summarized recent micro- and nanoscale mechanical testing methods applied to ion beam irradiated materials. Presented were testing techniques, nano-indentation, and micro-compression testing.

November 2007

MPA-10’s thermoacoustic-driven natural gas liquefier technology selected as winner in Wall Street Journal Technology Innovation Award, energy category

Los Alamos technology—developed by a team led my MPA-10’s Greg Swift—was recently named a winner in the Wall Street Journal Technology Innovation Awards, energy category. With a device designed to harness wasted or dormant energy resources, the team developed a method to liquefy natural gas through a thermoacoustic process that cools the gas with sound waves. The process differs from traditional methods because it produces smaller quantities but with much higher reliability and at lower cost. Los Alamos has licensed the technology to Swift LNG Inc., of Houston. According to a study done by the United States Government Accountability Office, every year about 3.3 trillion cubic feet of natural gas is flared or vented—burned wastefully or released into the atmosphere—across the globe, enough to meet the natural gas needs of France and Germany for a year. In addition, some 5,000 trillion cubic feet of undeveloped and unused natural gas deposits exist around the world in well fields that are too expensive to develop due to their size or location. Team members include Swift, Scott Backhaus, David Gardner, all MPA-10; Bill Ward, AET-6; John Gorman and Vince Kotsubo of Swift LNG; and Marc Oettinger of LANL Tech Transfer. More than 800 applications were submitted to the competition, which recognizes technology that represents a breakthrough from traditional methods, and not just an incremental improvement.

October 2007

Hosemann recognized for distinguished performance Contributions benefit Laboratory’s Advanced Fuel Cycle Initiative

MPA-10 Graduate Research Assistant Peter Hosemann is the 2007 recipient of the Student Distinguished Performance Award. Recognized for contributing significantly to several aspects of the Laboratory’s Advanced Fuel Cycle Initiative (AFCI) he received the award at the recent Student Symposium Banquet. Hosemann, a doctoral student from the University of Leoben in Austria, has been working on his dissertation at the Laboratory since 2005, studying radiation effects on steels in a heavy liquid metal environment. His research is supported by the Global Nuclear Energy Partnership program.

September 2007

Just back from Iraq, Tod Caldwell is recognized for Serving with distinction

Clear thinking under fire, overcoming cultural and language barriers during combat, and serving as a role model for military leadership and an ambassador of the American persona in one of the most dangerous provinces in Iraq earned Tod Caldwell the Bronze Star Medal, one of the US Armed Forces’ highest individual military decorations. The US Army Sergeant First Class recently returned to the Laboratory as a postdoctoral researcher in the Condensed Matter and Thermal Physics Group (MPA-10) after meritorious service to the country as a battalion advisor serving a year-long tour in Al Anbar Province and Baghdad. Duty calls A Virginia native, Caldwell joined the regular Army in 1986 right out of high school, specializing in military intelligence. He has written briefs which have gone to the President, the Joint Chiefs of Staff, and the United States European Command. Now a reservist, Caldwell, in June 2006, was called upon to use his knowledge and skills to train Iraqi Army staff and senior enlisted soldiers. But within mere weeks of arriving in the desert country he soon realized much more was required of him. When members of his team were wounded in an IED (improvised explosive device) attack, he assumed the role of communications advisor, developing the construction of a network that allowed Iraqi command and control personnel to secure a large area. He guided Iraqi Army staff in administrative duties that ensured day-to-day operations in a combat environment. He detained insurgents and questioned them in the field. He led combat patrols and operations that uncovered several weapons caches and IEDs prior to detonation. And he was repeatedly exposed to enemy fire while conducting counterinsurgency operations, which earned him the special recognition of the US Army’s Combat Action Badge.

August 2007

Thermoacoustically powered refrigerator to benefit residents of developing countries

Scott Backhaus, MPA-10, is part of an international collaboration developing a thermoacoustically driven refrigerator that can be used in rural areas where there are no sources of electrical power. The SCORE (Stove for Cooking, Refrigeration, and Electricity) device will burn wood to produce thermoacoustic energy that is used to provide refrigeration. The device will also provide heat for cooking as well as generate electricity. Thermoacoustics takes advantage of the way that sound waves can be produced when a gas is heated unevenly. In a thermoacoustic engine, such as the Stirling engine developed in the nineteenth century as an alternative to steam power, these pressure sound waves drive mechanical motion. This process may also run in reverse: the sound waves can be used to extract heat, pumping it from a cool source to a hot sink and thereby inducing cooling. One of the main attractions of SCORE stoves is that they don’t need an external electricity supply. Backhaus is working with a team led by researchers at the University of Nottingham in England. The project is funded by the Engineering and Physical Sciences Research Council, a United Kingdom governmental organization. The team plans to be producing the SCORE devices within fi ve years.

July 2007

MPA-10 NMR team completes first 235-U NMR at Los Alamos

Direct uranium (U) nuclear magnetic resonance (NMR) is difficult because the relaxation times are usually too fast, rendering the NMR signal invisible in many compounds. The relaxation times are short because the coupling between the nuclear spins and the electron spins are very large in 4f and 5f systems. If the electron spin dynamics can be sufficiently slowed down, the nuclear relaxation times can be long enough to allow detection. In the magnetically ordered state of 4f and 5f compounds, the electron spins become static, and NMR of the nuclear spins is possible. The NMR team successfully completed the first 235-U NMR at LANL. The team (Nicholas Curro and Seung Baek, both in MPA-10, with samples grown by Eric Bauer, MPA-10, Jason Cooley and James L. Smith, both in MST-6) has found the 235-U signal in an isotopically enriched sample of USb₂. In the antiferromagnetic state the U spins experience a static hyperfine field of 277 T. These results were presented at the 2007 International Conference on Strongly Correlated Electron Systems in Houston this month. The group plans to study the spectra and dynamics in a variety of other U based compounds, including the hidden order compound URu₂Si₂, and superconducting UPd₂Al₃, UPt₃, and UBe₁₃. LDRD supported the research.

May 2007

MPA-10 at 2007 APS March Meeting

The Materials Physics and Applications Division actively participated in the 2007 American Physical Society Meeting in Denver. Giving invited talks were MPA-10’s Tuson Park on “Field-induced Magnetism and Quantum Criticality in Superconducting CeRhIn5 under Pressure,” MPA-NHMFL’s Vivien Zapf on “Quantum Magnetism and Possible BEC (Bose Einstein Condensate) in an Organic Nickel Compound,” and MPA Division Leader John Sarrao on “Superconductivity: Challenges and Opportunities,” which was part of a symposium promoting DOE-Office of Basic Energy Science’s effort on Basic Research Needs for Superconductivity. In addition to Park’s invited talk, MPA-10 group members presented 12 contributed talks on such topics as quantum criticality in correlated electron systems, f-electron duality, novel superconductivity, the inhomogeneous superconducting FFLO (Fulde-Ferrell-Larkin-Ovchinnikov) state in pure and doped CeCoIn₅, and magnetic resonance force microscopy.

April 2007

MPA-10 team develops MRFM apparatus with unique temperature regulation capability

Magnetic resonance force microscopy (MRFM) is a hybrid between conventional magnetic resonance and cantilever- based scanning probes, utilizing an extreme sensitivity of cantilevers to drastically decrease the strength of a detectable signal. Recently, MRFM was used to detect a force signal originating from a single electron spin. It provides three dimensional imaging, excellent spatial resolution, and has been successfully used for detection of nuclear magnetic resonance (NMR), electron spin resonance (ESR) and ferromagnetic resonance (FMR) signals. At Los Alamos, MPA-10’s Evgueni Nazaretski and Roman Movshovich have developed an MRFM apparatus with unique temperature regulation capability between 4 and 100 K and in magnetic fields up to 6 T. The microscope allows three-dimensional scanning in the range of 6x6x6 mm with the nm-scale resolution and the force sensitivity of a few thousand electron spins. Substitution of a commercially available MFM cantilever for the MRFM cantilever will allow low temperature characterization of the static magnetization in the same apparatus. Recent experiments on a 200 nm-thick film of multiferroic TbMnO3 detected the resonance signal of Mn ions with the sensitivity at least seven orders of magnitude higher than that of conventional ESR methods, demonstrating MRFM utility as a tool of choice for studying dynamic magnetic properties of thin multiferroic films. The MRFM project is being funded by the LDRD office, both through Nazaretski’s Director’s-funded Postdoctoral Fellowship and through an ER headed by Movshovich.

March 2007

MPA-10’s Park to receive Postdoctoral Distinguished Performance Award

MPA-10's Tuson Park will receive on of two 2007 Postdoctoral Distinguished Perfarmance Awards. The award recognizes individuals whose outstanding performance has made a significant contribution to the Laboratory. Park, who joined the Laboratory in 2003 is an Oppenheimer Postdoctoral Fellow and a recipient of this year's Outstanding Young Researcher Award from the Association of Korean Physicists in America. He has a doctorate in physics form the Univeristy of Illinois at Urbana - Champaign.

March 2007

Kiplinger and Taylor named Los Alamos Stars

MPA-10’s Jaqueline Kiplinger and MPA-CINT Group Leader Toni Taylor have been selected as 2007 Los Alamos National Laboratory Stars. Presented by the Women’s Diversity Working Group, the awards recognize women who go above and beyond the call of duty in the performance of their job functions, who have achieved scientific or technical success, or who make important contributions to the community. Kiplinger came to Los Alamos in 1999 as the first Frederick Reines Distinguished postdoctoral fellow and is a technical staff member in MPA-10. An acknowledged expert in organometallic chemistry of actinides, Kiplinger has been invited to speak at prestigious conferences and universities and her work has been published in high profile publications— thus increasing the profile of Los Alamos actinide science. As a Laboratory scientific leader she has assembled and managed teams from across the Laboratory and has worked to improve the climate for science by mentoring young scientists and serving on the Science Council. Kiplinger was nominated by Eric Schelter, MPA-10, and Jackie Veauthier, C-IIAC, with input from Carol Burns, C-NR, and Tammy Taylor, NN.

March 2007

Park named Outstanding Young Researcher by Korean physicists' association

Tuson Park, an Oppenheimer Postdoctoral Fellow in MPA-10, has been selected for the 2007 Outstanding Young Researcher Award by the Association of Korean Physicists in America. Park is being recognized for his contributions to the field of correlated electron physics Park, who joined the Laboratory in 2003, has a doctorate in physics from the University of Illinois at Urbana-Champaign.

The OYRA award ceremony will take place at a joint reception with the APS Forum of International Physics and other expatriate physicists associations at the APS March Meeting in Denver. AKPA was launched in 1979 to promote scientific research in physics and to strenghten ties among Korean physicists in America.

Feb 2007

NMR team heavy fermion superconductor research reveals complex thermodynamic phase

MPA-10’s Nuclear Magnetic Resonance Team recently published its work on the heavy fermion superconductor CeCoIn₅ in Phys. Rev. Lett. 98, 036402 (2007). Postdoctoral researchers Ben-Li Young, now at National Chiao Tung University, Taiwan, Ricardo Urbano and team lead Nicholas Curro investigated the NMR spectra of CeCoIn₅ down to 40 mK in magnetic fields up to 12 T. At these temperatures and fields, this material undergoes a thermodynamic phase transition to a new state of matter. Bulk measurements have suggested that this phase is a new inhomogeneous superconducting state involving pairing of electrons on Fermi surfaces with unequal volumes. Such a state has been predicted to exist in certain condensed matter superconductors as well as within the core of neutron stars. The NMR measurements, however, reveal this phase is more complex, consisting of coexisting local moment magnetism and superconductivity. These results may provide clues for understanding the unusual normal state properties of this material and call for new theoretical investigations of the interplay of Kondo interactions, magnetism, and unconventional superconductivity. Authors of “Microscopic Evidence for Field-Induced Magnetism in CeCoIn₅,” also include MPA-10’s Joe Thompson; MPA-DO’s John Sarrao; A. B. Vorontsov, Louisiana State University; and Matthias Graf, T-11. An LDRD-ER funded this work.

Feb 2007

MPA well represented at actinides symposium of 2006 MRS Fall Meeting

The third actinide symposium for the Materials Research Society’s (MRS) fall meeting took place in Boston. This symposium was initiated in 2003 with participation form several national labs and universities interested in actinide research. Los Alamos National Laboratory and Lawrence Livermore National Laboratory have provided the funding for the symposium from inception and were the leading institutions for organizing the symposium. This year the symposium ran for four days with Los Alamos scientists making several presentations. Among the Los Alamos presenters, MPA Division Leader John Sarrao and MPA-10’s Joe Thompson gave a tutorial presentation. MST-6’s Jim Smith and Jason Lashley, MPA-10’s Nick Curro, and C-IIAC’s Sean Reilly gave invited presentations. The symposium covered the physics, chemistry and materials science of actinides from basic research to applications and technology. Details of the meeting including the technical program may be found at the MRS website (www.mrs.org) by following the links to the 2006 Fall meeting and Symposium OO: Actinides.

Jan 2007

MPA-10 researchers demonstrate unprecedented Th-mediated carbon-nitrogen coupling chemistry

MPA-10 researchers Eric Schelter and Jaqueline Kiplinger have discovered an unprecedented thorium-mediated reaction sequence that involves the coupling of four equivalents of 4-fluorobenzonitrile to yield an unusual eight-membered thorium(IV) tetraazametallacycle. The formation of carbon-nitrogen bonds remains a challenge for synthetic chemists; however, this reaction demonstrates that thorium is able to knit together several new C-N bonds. This transformation has no equivalent in transition metal chemistry and once again illustrates the unique chemical reactivity of the 5f-elements. This work was performed in collaboration with David Morris and Brian Scott of MPA-MC and will appear in Chemical Communications, a leading weekly journal for the publication of communications on important developments in the chemical sciences. The Los Alamos National Laboratory Laboratory-Directed Research and Development Program, the DOE-BES Heavy Element Chemistry Program, the Los Alamos National Laboratory G.T. Seaborg Institute for Transactinium Science, and a Director’s Postdoctoral Fellowship funded the research.

Dec 2006

MPA-10 gains Reines Fellow and Director's Postdoctoral Fellow

MPA-10’s Eric Schelter has been selected for a Reines Distinguished Postdoctoral Fellow appointment. Schelter earned his doctorate degree in inorganic chemistry from Texas A&M University. At Los Alamos he is researching magnetic and electronic properties in multimetallic f-element complexes. MPA-10’s Christopher Graves has been selected for a Director’s Postdoctoral Fellow appointment. Graves earned his doctorate in organic chemistry from Northwestern University. IN MPA-10, he is researching organometallic synthesis of actinide complexes.

Dec 2006

MPA-10 develops new capabilities in actinide photoemission

Photoemission is a measurement technique useful in electronic structure investigations. Fine details of the momentum- dependent electronic structure may be revealed by use of the modern high-resolution analyzers, capable of resolving electron energy and momentum simultaneously. This technique, known as angle-resolved photoemission spectroscopy (ARPES), turned outto be of substantial importance in increasing understanding of several phenomena in the correlated electron systems, e.g. unconventional superconductivity. However, researchers are only beginning to unravel the details of the electronic structure of 5f systems. Due to the complications introduced by radioactive samples no ARPES analyzer was ever used for transuranic materials. The photoemission team in MPA-10, led by John Joyce with Tomasz Durakiewicz and Kevin Graham, is assembling the first ARPES system for transuranic materials. The new system is based on the Phoibos 150 hemispherical analyzer, with energy resolution of less than 5meV and momentum resolution better than 0.2 degrees. In addition to the availability of momentum resolution, an order of magnitude increase in energy resolution is expected compared to the previously utilized angle-integrated instrument. He lamp, UV laser and laser plasma light source will be utilized as excitation sources. The team is working on maintaining the UHV conditions through baking and testing of each component. The first transuranic samples will be measured in early 2007.

Nov 2006

Significant MPA presence at international conference on magnetism

Six MPA-10 researchers presented their work on correlated electron materials physics at the International Conference on Magnetism held recently in Kyoto, Japan. Joe Thompson presented a plenary talk on the magnetism and unconventional superconductivity exhibited by isostructural cerium and plutonium “115” compounds. Eric Bauer discussed his research on magnetism and crystalline electric fields in cubic ternary uranium zinc compounds, and Filip Ronning presented his thermodynamic and electronic transport study on magnetic excitations in the two-dimensional spin layer present in Sm(La,Sr)CuO₄. Yoshi Tokiwa presented his low-temperature magnetization and specific-heat study of YbIn_1-xRh_xCu₄ and discussed the relationship between ferromagnetic correlations and non-Fermi liquid behavior around the critical concentration x = 0.6. Evgueni Nazaretski presented magnetic resonance force microscopy studies in thin permalloy films that was carried out in a collaboration involving researchers in MPA-10, Ohio State University, the University of Alabama, and the Naval Research Laboratory. Tuson Park presented research on “Upper critical field scaling near quantum critical point in the heavy fermion compound CeRhIn₅.”

At the conference from NHMFL, Neil Harrison discussed itinerant hidden order and qusiparticles in URu₂Si₂. Peter Sharma discussed magnetic-field dependent elasticity at the “strain glass” transition in La_5/8-xPr_xCa_3/8MnO₃" and Marcelo Jaime presented work on non-local magnetic field-tuned quantum criticality in cubic CeIn_3-xsub>Sn_x(x=0.25).

Sep 2006

The First International Workshop on the Dual Nature of f-Electrons

Researchers from around the globe gathered in Santa Fe last week to confront one of the most challenging questions in modern condensed matter physics­the dual nature of f-electrons.

Presenting the current state of research and facilitate discussion focused on the dual nature of f-electrons in a multitude of systems the First International Workshop on the dual Nature of f-Electrons was sponsored by Los Alamos National Laboratory’s Seaborg Institute and the Laboratory Directed Research and Development program, and the Department of Energy’s Office of Science and Office of Basic Energy Sciences.

Dual Nature workshop logo.

The dual nature of f-electrons may be seen differently, depending on the use of experimental or theoretical techniques, but, in general, it manifests itself in the ability of f-electrons to be simultaneously localized and itinerant (band-like) in the same system. Several experiments and some theory argue precisely for this seemingly contradictory duality. Los Alamos National Laboratory is a leader in f-electrons research, including the various aspects of duality.

The workshop drew 35 national and international scientists who participated in invited talks and roundtable discussions aimed at a better understanding of the physical consequences of duality. This understanding has the potential to change the conceptual framework of the physics of strongly correlated materials.

Organizers were Tomasz Durakiewicz, MPA-10, and Cristian Batista, T-11. Co-organizer was Gertrud Zwicknagl of Germany’s Technische Universität Braunschweig. Organizers intend to continue the workshop biennially.

More information about the workshop, including program and speakers, may be found at: http://public.lanl.gov/tomasz/dual/dual.html.
July 2006

International magnetism conference to feature plenary talk by Joe Thompson

Joe Thompson will give a plenary talk at the 17th International Conference on Magnetism (ICM 2006) to be held in Kyoto, Japan August 20-25.

He will discuss recent results that point to coexisting magnetism and unconventional superconductivity in isostructural cerium and plutonium compounds.
The triennial meeting is dedicated to the presentation and discussion of the latest developments and ideas relevant to magnetic and related materials and is organized under the auspices of the International Union for Pureand applied Physics.

May 2006

MPA-10 TEAMS

Thermal Physics

• Thermoacoustics
• Nonlinear Dynamics
• Advanced Fuel Cycle Initiative R&D

Correlated Electrons

• Materials Synthesis and Characterization
• Transport and Thermodynamics
• Novel Materials at Extreme Conditions
• Very Low Temperature Physics

Actinide Chemistry

• Heavy-Element Chemistry

Low Energy Spectroscopy

• Condensed Matter NMR
• Photoelectron Spectroscopy
• Magnetic Resonance Force Microscopy
• Mossbauer Spectroscopy
• Neutron Scattering