Professor Tom Lancaster's Outputs (121)

Quantum magnetism in molecular spin ladders probed with muon-spin spectroscopy (2018)
Journal Article
Lancaster, T., Xiao, F., Huddart, B., Williams, R., Pratt, F., Blundell, S., Clark, S., Scheuermann, R., Goko, T., Ward, S., Manson, J., Rüegg, C., & Krämer, K. (2018). Quantum magnetism in molecular spin ladders probed with muon-spin spectroscopy. New Journal of Physics, 20(10), Article 103002. https://doi.org/10.1088/1367-2630/aae21a

We present the results of muon-spin spectroscopy (μ +SR) measurements on the molecular spin ladder system (Hpip)2CuBr4(1−x)Cl4x , [Hpip = (C5H12N)]. Using transverse field μ +SR we are able to identify characteristic behaviour in each of the regions... Read More about Quantum magnetism in molecular spin ladders probed with muon-spin spectroscopy.

Magnetic phases of skyrmion-hosting GaV4S8−ySey (y = 0, 2, 4, 8) probed with muon spectroscopy (2018)
Journal Article
Franke, K. J., Huddart, B. M., Hicken, T. J., Xiao, F., Blundell, S. J., Pratt, F. L., Crisanti, M., Barker, J. A., Clark, S. J., Štefančič, A., Hatnean, M. C., Balakrishnan, G., & Lancaster, T. (2018). Magnetic phases of skyrmion-hosting GaV4S8−ySey (y = 0, 2, 4, 8) probed with muon spectroscopy. Physical Review B, 98(5), Article 054428. https://doi.org/10.1103/physrevb.98.054428

We present the results of a muon-spin spectroscopy investigation of GaV4S8−ySey with y = 0, 2, 4, and 8. Zero-field measurements suggest that GaV4Se8 and GaV4S8 have distinct magnetic ground states, with the latter material showing an anomalous tempe... Read More about Magnetic phases of skyrmion-hosting GaV4S8−ySey (y = 0, 2, 4, 8) probed with muon spectroscopy.

Microscopic effects of Dy doping in the topological insulator Bi2Te3 (2018)
Journal Article
Duffy, L., Steinke, N., Krieger, J., Figueroa, A., Kummer, K., Lancaster, T., …Hesjedal, T. (2018). Microscopic effects of Dy doping in the topological insulator Bi2Te3. Physical Review B, 97(17), Article 174427. https://doi.org/10.1103/physrevb.97.174427

Magnetic doping with transition metal ions is the most widely used approach to break time-reversal symmetry in a topological insulator (TI)—a prerequisite for unlocking the TI’s exotic potential. Recently, we reported the doping of Bi2Te3 thin films... Read More about Microscopic effects of Dy doping in the topological insulator Bi2Te3.

Implications of bond disorder in a S=1 kagome lattice (2018)
Journal Article
Manson, J. L., Brambleby, J., Goddard, P. A., Spurgeon, P. M., Villa, J. A., Liu, J., …Noll, B. (2018). Implications of bond disorder in a S=1 kagome lattice. Scientific Reports, 8(1), Article 4745. https://doi.org/10.1038/s41598-018-23054-6

Strong hydrogen bonds such as F···H···F offer new strategies to fabricate molecular architectures exhibiting novel structures and properties. Along these lines and, to potentially realize hydrogen-bond mediated superexchange interactions in a frustra... Read More about Implications of bond disorder in a S=1 kagome lattice.

Quantum mechanical tunneling in the automerization of cyclobutadiene (2018)
Journal Article
Schoonmaker, R., Lancaster, T., & Clark, S. (2018). Quantum mechanical tunneling in the automerization of cyclobutadiene. The Journal of Chemical Physics, 148(10), Article 104109. https://doi.org/10.1063/1.5019254

Cyclobutadiene has a four-membered carbon ring with two double bonds, but this highly strained molecular configuration is almost square and, via a coordinated motion, the nuclei quantum mechanically tunnels through the high-energy square state to a c... Read More about Quantum mechanical tunneling in the automerization of cyclobutadiene.

Static and Fluctuating Magnetic Moments in the Ferroelectric Metal LiOsO3 (2018)
Presentation / Conference Contribution
Kirschner, F. K., Lang, F., Pratt, F. L., Lancaster, T., Shi, Y., Guo, Y., Boothroyd, A. T., & Blundell, S. J. (2018, December). Static and Fluctuating Magnetic Moments in the Ferroelectric Metal LiOsO3. Presented at 14th International Conference on Muon Spin Rotation, Relaxation and Resonance (μSR2017), Sapporo

LiOsO3 is the first example of a new class of material called a ferroelectric metal. We performed zero-field and longitudinal-field μSR, along with a combination of electronic structure and dipole field calculations, to determine the magneticground s... Read More about Static and Fluctuating Magnetic Moments in the Ferroelectric Metal LiOsO3.

Strong Coupling of Microwave Photons to Antiferromagnetic Fluctuations in an Organic Magnet (2017)
Journal Article
Mergenthaler, M., Liu, J., Le Roy, J. J., Ares, N., Thompson, A. L., Bogani, L., …Laird, E. A. (2017). Strong Coupling of Microwave Photons to Antiferromagnetic Fluctuations in an Organic Magnet. Physical Review Letters, 119(14), Article 147701. https://doi.org/10.1103/physrevlett.119.147701

Coupling between a crystal of di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium radicals and a superconducting microwave resonator is investigated in a circuit quantum electrodynamics (circuit QED) architecture. The crystal exhibits paramagnetic behavior... Read More about Strong Coupling of Microwave Photons to Antiferromagnetic Fluctuations in an Organic Magnet.

Local magnetism and spin dynamics of the frustrated honeycomb rhodate Li2RhO3 (2017)
Journal Article
Khuntia, P., Manni, S., Foronda, F., Lancaster, T., Blundell, S., Gegenwart, P., & Baenitz, M. (2017). Local magnetism and spin dynamics of the frustrated honeycomb rhodate Li2RhO3. Physical Review B, 96(9), Article 094432. https://doi.org/10.1103/physrevb.96.094432

We reportmagnetization, heat capacity, 7Li nuclear magnetic resonance (NMR), and muon-spin rotation (μSR) measurements on the honeycomb 4d5 spin liquid candidate Li2RhO3. The magnetization in small magnetic fields provides evidence of the partial spi... Read More about Local magnetism and spin dynamics of the frustrated honeycomb rhodate Li2RhO3.

Exchange constants in molecule-based magnets derived from density functional methods (2017)
Journal Article
Thomas, I., Clark, S., & Lancaster, T. (2017). Exchange constants in molecule-based magnets derived from density functional methods. Physical Review B, 96(9), Article 094403. https://doi.org/10.1103/physrevb.96.094403

Cu(pyz)(NO3)2 is a quasi-one-dimensional molecular antiferromagnet that exhibits three-dimensional long-range magnetic order below T N = 110 mK due to the presence of weak interchain exchange couplings. Here, we compare calculations of the three larg... Read More about Exchange constants in molecule-based magnets derived from density functional methods.

Crystal structure and magnetic modulation in β−Ce2O2FeSe2 (2017)
Journal Article
Wang, C., Ainsworth, C., Champion, S., Stewart, G., Worsdale, M., Lancaster, T., …Evans, J. S. (2017). Crystal structure and magnetic modulation in β−Ce2O2FeSe2. Physical Review Materials, 1(3), Article 034403. https://doi.org/10.1103/physrevmaterials.1.034403

We report a combination of X-ray and neutron diffraction studies, Mossbauer spectroscopy and muon spin relaxation (muSR) measurements to probe the structure and magnetic properties of the semiconducting beta-Ce2O2FeSe2 oxychalcogenide. We report a ne... Read More about Crystal structure and magnetic modulation in β−Ce2O2FeSe2.

Quantum Griffiths phase inside the ferromagnetic phase of Ni1-xVx (2017)
Journal Article
Wang, R., Gebretsadik, A., Ubaid-Kassis, S., Schroeder, A., Vojta, T., Baker, P. J., …Page, K. (2017). Quantum Griffiths phase inside the ferromagnetic phase of Ni1-xVx. Physical Review Letters, 118(26), Article 267202. https://doi.org/10.1103/physrevlett.118.267202

We study by means of bulk and local probes the d-metal alloy Ni1-xVx close to the quantum critical concentration, x_c \approx 11.6\%, where the ferromagnetic transition temperature vanishes. The magnetization-field curve in the ferromagnetic phase ta... Read More about Quantum Griffiths phase inside the ferromagnetic phase of Ni1-xVx.

Room-temperature helimagnetism in FeGe thin films (2017)
Journal Article
Zhang, S., Stasinopoulos, I., Lancaster, T., Xiao, F., Bauer, A., Rucker, F., …Hesjedal, T. (2017). Room-temperature helimagnetism in FeGe thin films. Scientific Reports, 7(1), Article 123. https://doi.org/10.1038/s41598-017-00201-z

Chiral magnets are promising materials for the realisation of high-density and low-power spintronic memory devices. For these future applications, a key requirement is the synthesis of appropriate materials in the form of thin films ordering well abo... Read More about Room-temperature helimagnetism in FeGe thin films.

The Use of Downward Causation in Condensed Matter Physics (2017)
Book Chapter
Clark, S., & Lancaster, T. (2017). The Use of Downward Causation in Condensed Matter Physics. In M. P. Paoletti, & F. Orilia (Eds.), Philosophical and scientific perspectives on downward causation (131-145). Routledge

Elucidation of the helical spin structure of FeAs (2017)
Journal Article
Frawley, T., Schoonmaker, R., Lee, S., Du, C., Steadman, P., Strempfer, J., …Hatton, P. (2017). Elucidation of the helical spin structure of FeAs. Physical Review B, 95(6), Article 064424. https://doi.org/10.1103/physrevb.95.064424

We present the results of resonant x-ray scattering measurements and electronic structure calculations on the monoarsenide FeAs. We elucidate details of the magnetic structure, showing the ratio of ellipticity of the spin helix is larger than previou... Read More about Elucidation of the helical spin structure of FeAs.

Adiabatic physics of an exchange-coupled spin-dimer system: Magnetocaloric effect, zero-point fluctuations, and possible two-dimensional universal behavior (2017)
Journal Article
Brambleby, J., Goddard, P., Singleton, J., Jaime, M., Lancaster, T., Huang, L., …Manson, J. (2017). Adiabatic physics of an exchange-coupled spin-dimer system: Magnetocaloric effect, zero-point fluctuations, and possible two-dimensional universal behavior. Physical Review B, 95(2), Article 024404. https://doi.org/10.1103/physrevb.95.024404

We present the magnetic and thermal properties of the bosonic-superfluid phase in a spin-dimer network using both quasistatic and rapidly changing pulsed magnetic fields. The entropy derived from a heat-capacity study reveals that the pulsed-field me... Read More about Adiabatic physics of an exchange-coupled spin-dimer system: Magnetocaloric effect, zero-point fluctuations, and possible two-dimensional universal behavior.

Quantum-critical spin dynamics in a Tomonaga-Luttinger liquid studied with muon-spin relaxation (2017)
Journal Article
Möller, J., Lancaster, T., Blundell, S., Pratt, F., Baker, P., Xiao, F., …Landee, C. (2017). Quantum-critical spin dynamics in a Tomonaga-Luttinger liquid studied with muon-spin relaxation. Physical Review B, 95(2), Article 020402(R). https://doi.org/10.1103/physrevb.95.020402

We demonstrate that quantum-critical spin dynamics can be probed in high magnetic fields using muon-spin relaxation (μ+SR). Our model system is the strong-leg spin ladder bis(2,3-dimethylpyridinium) tetrabromocuprate (DIMPY). In the gapless Tomonaga-... Read More about Quantum-critical spin dynamics in a Tomonaga-Luttinger liquid studied with muon-spin relaxation.

Effect of disorder on a pressure-induced z = 1 magnetic quantum phase transition (2016)
Journal Article
Mannig, A., Möller, J., Thede, M., Hüvonen, D., Lancaster, T., Xiao, F., …Zheludev, A. (2016). Effect of disorder on a pressure-induced z = 1 magnetic quantum phase transition. Physical Review B, 94(14), Article 144418. https://doi.org/10.1103/physrevb.94.144418

Pressure-induced ordering close to a z=1 quantum-critical point is studied in the presence of bond disorder in the quantum spin system (C4H12N2)Cu2(Cl1−xBrx)6 (PHCX) by means of muon-spin rotation and relaxation. As for the pure system (C4H12N2)Cu2Cl... Read More about Effect of disorder on a pressure-induced z = 1 magnetic quantum phase transition.

Bimetallic MOFs (H3O)x[Cu(MF6)(pyrazine)2]·(4 − x)H2O (M = V4+, x = 0; M = Ga3+, x = 1): co-existence of ordered and disordered quantum spins in the V4+ system (2016)
Journal Article
Manson, J. L., Schlueter, J. A., Garrett, K. E., Goddard, P. A., Lancaster, T., Möller, J. S., …Baines, C. (2016). Bimetallic MOFs (H3O)x[Cu(MF6)(pyrazine)2]·(4 − x)H2O (M = V4+, x = 0; M = Ga3+, x = 1): co-existence of ordered and disordered quantum spins in the V4+ system. Chemical Communications, 52(85), 12653-12656. https://doi.org/10.1039/c6cc05873f

The title compounds are bimetallic MOFs containing [Cu(pyz)2]2+ square lattices linked by MF6n− octahedra. In each, only the Cu2+ spins exhibit long-range magnetic order below 3.5 K (M = V4+) and 2.6 K (M = Ga3+). The V4+ spins remain disordered down... Read More about Bimetallic MOFs (H3O)x[Cu(MF6)(pyrazine)2]·(4 − x)H2O (M = V4+, x = 0; M = Ga3+, x = 1): co-existence of ordered and disordered quantum spins in the V4+ system.

La2SrCr2O7: Controlling the Tilting Distortions of n=2 Ruddlesden-Popper Phases through A-Site Cation Order (2016)
Journal Article
Zhang, R., Abbett, B., Read, G., Lang, F., Lancaster, T., Tran, T., …Hayward, M. (2016). La2SrCr2O7: Controlling the Tilting Distortions of n=2 Ruddlesden-Popper Phases through A-Site Cation Order. Inorganic Chemistry, 55(17), 8951-8960. https://doi.org/10.1021/acs.inorgchem.6b01445

The n = 2 Ruddlesden−Popper phase La2SrCr2O7 adopts a highly unusual structural configuration in which the cooperative rotations of the CrO6 octahedra are out of phase in all three Cartesian directions (ΦΦΦz/ΦΦΦz; a−a−c−/a−a−c−). First-principles DFT... Read More about La2SrCr2O7: Controlling the Tilting Distortions of n=2 Ruddlesden-Popper Phases through A-Site Cation Order.

Nanoscale depth-resolved polymer dynamics probed by the implantation of low energy muons (2016)
Journal Article
Pratt, F. L., Lancaster, T., Baker, P. J., Blundell, S. J., Prokscha, T., Morenzoni, E., …Assender, H. E. (2016). Nanoscale depth-resolved polymer dynamics probed by the implantation of low energy muons. Polymer, 105, 516-525. https://doi.org/10.1016/j.polymer.2016.07.078

The low energy muon (LEM) technique has been used to probe local changes in the dynamical spectrum of thin film polymer samples taking place as a function of the temperature and the implantation depth below the free surface. The studies have been mad... Read More about Nanoscale depth-resolved polymer dynamics probed by the implantation of low energy muons.