Mines Repository (Colorado School of Mines)
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Native silver in calcite
No full textPhotographed by Ron Wolf.Wires of native silver in white calcite
Rhodochrosite on quartz
No full textPhotographed by Ron Wolf.Pink rhodochrosite coating prisms of quartz, Pachapaqui district, Bolognesi Province, Ancash Department, Peru.
Hematite pseudomorph after siderite
No full textPhotographed by Ron Wolf.Grey brown resinous hematite pseudomorph after siderite, Lake George intrusive center, Pikes Peak batholith, Teller County, Colorado
Sea urchin – Phymosoma texanum
No full textPhotographed by Ron Wolf.Fossil sea urchin with stubbly surface
Fish – Diplomystus humilus
No full textPhotographed by Ron Wolf.Fossil fish showing anatomical details of bones, fins, and head, on fine matrix
Measurement system for in situ application of strain in silicon and silicon–germanium quantum dots, A
No full textIncludes bibliographical references.2025 Spring.Engineering tunable valley splitting in silicon/silicon–germanium quantum-dot spin qubits is a central route to suppressing spin–valley leakage, minimizing charge-noise sensitivity, and extending coherence times to the fault-tolerant regime. Here we develop and characterize a cryogenic measurement platform to engineer this valley splitting via uniaxial strain applied in situ to foundry-fabricated Tunnel Falls qubit chips. Strain is transferred through commercial longitudinal piezoelectric actuators and calibrated with four-wire measurement and a temperature-compensated Wheatstone bridge employing modified-Karma nickel–chromium gauges. Four-wire resistance and balanced-bridge readouts enable microstrain resolution from a room-temperature environment down to cryogenic temperatures.
Thermal and mechanical anchoring of the actuators to a stage presents challenges to prevent restriction of the actuator stroke and hence the applied strain. We design a two-piece stage that allows for easy loading of the actuators into a dilution refrigerator while providing the required anchoring. Finite-element simulations of the stage predict suppression of stray electrostatic fields by more than one order of magnitude at the device surface, helping to ensure that gate-defined potentials remain unperturbed while the crystal lattice is distorted.
Our platform enables quantitative tests of deformation-potential and interface-roughness theories that predict how strain modifies the valley–orbit coupling parameter and, consequently, the spin relaxation and coherence times. Utilizing electrically driven strain therefore opens a path toward large, tunable valley splitting, important for future large-scale CMOS-compatible quantum processors
Cooks Peak mining district, Luna County, New Mexico
No full textMine report no. 1838.Typescript (carbon copy).One report is dated 1914; the other is undated.Title supplied by cataloger.A report upon the Cooks Peak mining district / J.L. Daniels -- Location of the Cooks Peak mining district / H.F. Jones
Lake Hattie irrigation project, Albany County, Wyoming
No full textMine report no. 1955.Typescript (carbon copy) and handwritten material.Title supplied by cataloger.Daily mean gage height and discharge of Little Laramie river at Filmore for 1912 -- Map of Lake Hattie irrigation project near Laramie Wyoming
Dolly Varden district
No full textMine report no. 1807.Typescript (carbon copy) and handwritten version of report