Wayne Itano

University of Colorado Boulder | CUB · Museum of Natural History

Supplementary data used in this study, including a review of over 60 cases of body size estimation controversies in fossil animals.

Body size is of fundamental importance to our understanding of extinct organisms. Physiology, ecology and life history are all strongly influenced by body size and shape, which ultimately determine how a species interacts with its environment. Reconstruction of body size and form in extinct animals provides insight into the dynamics underlying comm...

Martin Lockley is best known for his studies of ichnology. However, early in his career, he made contributions to the vertebrate paleontology of the Minturn Formation (Middle Pennsylvanian) ner McCoy, in central Colorado.

Teeth from the late Mississippian Bangor Limestone, Monteagle Limestone, and Pride Mountain Formation (early to middle Chesterian = late Viséan–early Serpukhovian) of northern Alabama, USA, are designated as Cavusodus whitei, gen. et sp. nov. The species is similar to Cypripediodens cristatus Duffin and Ward, known only from the Eyam Limestone Form...

Squaloraja is a genus of chimaeriform fishes known from the Early Jurassic. It has a dorsoventrally flattened body and a long median rostral cartilage. Males have a lance-like tenaculum that articulates with a central groove on the dorsal face of the median rostral cartilage. The genus is the only member of the family Squalorajidae, itself the only...

Restudy of Campyloprion annectans Eastman, 1902 from North America demonstrated that neither specimen included is diagnostic at the species level; thus, the species name is a nomen dubium. Since this species was designated as the type species of the genus, this requires suppression of the generic name also. Another species earlier assigned to Campy...

Remains of the chondrichthyan Psephodus Morris and Roberts, 1862, consist mainly of isolated tooth plates. The genus has a range from Late Devonian (Famennian) to Late Mississippian (Serpukhovian). The most complete specimen is a partially articulated set of teeth and tooth plates of the type species, P. magnus, from the early Serpukhovian of East...

A talk for a nonspecialist audience about the paleontology of the Minturn Formation (Middle Pennsylvanian) in the vicinity of McCoy, Eagle County, Colorado.

This article is one in a series that highlights fossil species named after members of WIPS. This month I relate the story of a fossil crinoid, Sciadiocrinus wipsorum, named after the Western Interior Paleontological Society (WIPS) itself.

The validity of the chondrichthyan species Petalodus ohioensis Safford 1853, has long been in doubt due to the poor quality of the published figures and the unknown whereabouts of the holotype. That situation changed with the discovery of casts of the holotype in the collections of the Yale Peabody Museum of Natural History. The quality of the cast...

The holotype of Psephodus minutus Wellburn, 1901, from the Millstone Grit Group (Carboniferous, Lower Pennsylvanian Series, Marsdenian Substage) of Lancashire (now Greater Manchester), England, was originally interpreted as a set of three articulated tooth plates of a chondrichthyan fish. No figure was published with the description, though a drawi...

The symphyseal tooth whorls of the Carboniferous chondrichthyan Edestus consist of files of teeth having sharply-pointed, serrated crowns, joined at their bases. A single tooth whorl was present in each jaw. How these tooth whorls functioned is unclear, since their convex curvature allows only a few of the most lingual crowns of opposing tooth whor...

In a previous article, published in Trilobite Tales, I told the story of my attempts to identify a fossil from the Hunsrück Slate erroneously labeled as an Edestus tooth whorl, found in the collections of the Natural History Museum in London. In this article, also published in Trilobite Tales, I present new evidence that it is an ammonoid.

Only a crude line drawing of the holotype tooth of the shark Petalodus ohioensis Safford, 1853 has ever been published, and the location of that specimen has long been unknown. The discovery of a cast of the holotype in the collections of the Yale Peabody Museum of Natural History demonstrates that P. alleghaniensis Leidy, 1856, is a junior subject...

Paleontologists think they know what a Lagerstätte is, but few have read Seilacher (1970) in the original German for the original definition. I translate Seilacher's definitions into English and consider the question as to whether a trace-fossil site can be called a Lagerstätte.

The term 'quantum Zeno paradox' or 'quantum Zeno effect' refers to the slowing down of the evolution of a quantum system as it is observed more and more frequently. In 1977, Misra and Sudarshan gave a theoretical demonstration of its existence. There has been disagreement regarding the definition of the effect and whether it is really a paradox, re...

A fossil, labeled as an Edestus "dental spiral" was found in the collections of the Natural History Museum in London. It was not Edestus, and not even a vertebrate. It might be an invertebrate body fossil or a trace fossil.

Only a crude line drawing of the holotype tooth of the shark Petalodus ohioensis Safford, 1853 has ever been published, and the location of that specimen has long been unknown. The discovery of a cast of the holotype in the collections of the Yale Peabody Museum of Natural History demonstrates that P. alleghaniensis Leidy, 1856, is a junior subject...

Background: Paleozoic holocephalian tooth plates are rarely found articulated in their original positions. When they are found isolated, it is difficult to associate the small, anterior tooth plates with the larger, more posterior ones. Tooth plates are presumed to have evolved from fusion of tooth files. However, there is little fossil evidence f...

Campyloprion is a late Paleozoic shark similar to Helicoprion, but less well known. This article tells the story of the new finds and museum visits that led to a publication.

Edestus is a Middle Pennsylvanian chondrichthyan possessing symphyseal tooth whorls in both the upper and lower jaws. The curvature of the tooth whorls prevents most of the crowns of the opposing whorls from occluding with each other. For that reason, it has recently been hypothesized that the tooth whorls were used to slash prey with a vertical mo...

Campyloprion Eastman, 1902 is a chondrichthyan having an arched symphyseal tooth whorl similar to that of Helicoprion Karpinsky, 1899, but less tightly coiled. The holotype of Campyloprion annectans Eastman, 1902, the type species of Campyloprion, is of unknown provenance, but is presumed to be from the Pennsylvanian of North America. Campyloprion...

We evaluate the electric quadrupole moments of the ${^1}\!S_0$ and ${^3}\!P_0$ clock states of $^{27}$Al$^+$ and $^{115}$In$^+$. To capture all dominant contributions, our analysis extends through third order of perturbation theory and includes hyperfine coupling of the electrons to both the magnetic dipole and electric quadrupole moments of the nu...

A holocephalan tooth plate having nearly perfect bilateral symmetry is reported from the Mississippian Bangor Limestone of Franklin County, Alabama. The symmetry indicates that it occupied a symphyseal, or possibly parasymphyseal, position. Symphyseal dentitions have rarely been reported in holocephalan chondrichthyans, but are not unknown, e.g., t...

The paired symphyseal tooth whorls of the Carboniferous chondrichthyan Edestus are perhaps the most enigmatic dental structures of any known vertebrate. The tooth whorls have been compared to scissors or to saw blades. It is commonly held that the tooth whorls were used in opposition, to cut prey caught between them. However, the curvature of the w...

An unidentified fossil fish bit given for free by an eBay dealer turns out to be a spine of the Mississippian shark Erismacanthus maccoyanus

Several imaging techniques are applied to studies of teeth of Edestus, a Carboniferous chondrichthyan fish. The techniques described are SEM (scanning electron microscopy), manual scanning macro photography combined with digital image stitching, and HDR (high dynamic range) photography.

Two incomplete teeth of the chondrichthyan genus Edestus are reported. They were collected from the Gray Mesa Formation (Pennsylvanian, late Desmoinesian), Socorro County, New Mexico, in 1996. The better-preserved tooth belongs to Edestus sp. cf. E. heinrichi. The other cannot be identified beyond the generic level. These are the first specimens of...

The observation of intermittent fluorescence of a single atomic ion, a phenomenon better known as ‘macroscopic quantum jumps,’ was an important early scientific application of the three-dimensional rf quadrupole (Paul) trap. The prediction of the phenomenon by Cook and Kimble grew out of a proposal by Dehmelt for a sensitive optical double-resonanc...

Edestus is a Carboniferous chondrichthyan genus known mainly from its triangular, serrated teeth. A maximum of around ten teeth are joined at their bases to form tooth whorls. Edestus minor Newberry, 1866, was described on the basis of a single, isolated tooth. A tooth whorl containing seven teeth, described and figured by Hitchcock in 1856, but no...

Edestus is a Carboniferous chondrichthyan genus known mainly from its triangular, serrated teeth. A maximum of around ten teeth are joined at their bases to form tooth whorls. Edestus minor Newberry, 1866, was described on the basis of a single, isolated tooth. A tooth whorl containing seven teeth, described and figured by Hitchcock in 1856, but no...

A chondrichthyan tooth having a serrated edge, from the Late Pennsylvanian of Xinjiang Uyghur Autonomous Region, China, was identified as Edestus sp. [Cheng, Z., Lucas, S.G., Zidek, J., 1996. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1996 (11), 701-707]. Because of the lack of bilateral symmetry, the tooth does not belong to Edestu...

An isolated tooth belonging to the chondrichthyan genus Edestus Leidy 1856, has been found near Bollington, Cheshire, England, in beds of the Yeadonian Substage of the Namurian Stage (Bashkirian Standard Stage, Pennsylvanian Subsystem). The tooth is tentatively referred to Edestus newtoni Woodward 1917, based on similarity of the crown morphology t...

I spent Christmas 2011 in London, visiting my daughter Nicole, who lives there with her husband. I had made arrangements beforehand to visit the fossil fish collections at the Natural History Museum. I found there a specimen, labeled Edestus sp., from the lower Devonian of Germany, which was clearly mislabeled. Edestus is a strange shark, known onl...

Teeth of many extant and extinct chondrichthyans have serrated edges (carinae). The extensive literature on dental abnormalities in Recent and fossil sharks does not appear to include any descriptions of split or supernumerary serration rows. A tooth of the Carboniferous chondrichthyan Edestus minor has two anomalies: a serrated carina that splits...

The species of Edestus Leidy (Chondrichthyes, Edestidae) are divided into two groups: those close to Edestus minor Newberry and those close to Edestus heinrichi Newberry and Worthen. The occurrences of Edestus worldwide (North America, Britain and Russia) are reviewed. In North America, Edestus occurs in the Illinois Basin and in the western United...

We report an experimental determination of the diamagnetic correction to the $^9$Be$^+$ ground state hyperfine constant $A$. We measured $A$ = $-625\,008\,837.371(11)$ Hz at a magnetic field $B$ of 4.4609 T. Comparison with previous results, obtained at lower values of $B$ (0.68 T and 0.82 T), yields the diamagnetic shift coefficient $k$ = $2.63(18...

We report an experimental determination of the diamagnetic correction to the 9 Be + ground state hyperfine constant A. We measured A = −625 008 837.371(11) Hz at a magnetic field B of 4.4609 T. Comparison with previous results, obtained at lower values of B (0.68 T and 0.82 T), yields the diamagnetic shift coefficient k = 2.63(18) × 10 −11 T −2 , w...

We describe experimental and theoretical studies of open-loop quantum control techniques known as dynamical decoupling (DD) for the suppression of decoherence-induced errors in quantum systems. Our experiments on trapped atomic ion qubits demonstrate that it is possible to optimize the construction of DD sequences for a given noise power spectral d...

Frequency standards based on narrow optical transitions in 27 Al+ and 199Hg+ ions have been developed at NIST. Both standards have absolute reproducibil­ ities of a few parts in 10 17 . This is about an order of magnitude better than the fractional uncertainty of the SI second, which is based on the 133Cs hyper­ fine frequency. Use of femtosecond l...

Frequency standards (atomic clocks) based on narrow optical transitions in 27Al+ and 199Hg+ have been developed over the past several years at NIST. Both types of standards are based on single ions confined in Paul traps, but differ in the methods used to prepare and detect the internal atomic states. Al+ lacks a strong, laser-accessible transition...

We discuss the use of two-dimensional $^{9}$Be$^{+}$ ion crystals for experimental tests of quantum control techniques. Our primary qubit is the 124 GHz ground-state electron spin flip transition, which we drive using microwaves. An ion crystal represents a spatial ensemble of qubits, but the effects of inhomogeneities across a typical crystal are...

Any quantum system, such as those used in quantum information or magnetic resonance, is subject to random phase errors that can dramatically affect the fidelity of a desired quantum operation or measurement. In the context of quantum information, quantum error correction techniques have been developed to correct these errors, but resource requireme...

We study the optimization of dynamical decoupling sequences using ^9Be^+ ions in a Penning ion trap. We artificially synthesize the noise environment the ions see to emulate a variety of physical systems. By incorporating measurement feedback with a Nelder-Mead search algorithm, our locally optimized dynamical decoupling sequences (LODD) attain an...

We present a detailed experimental study of the Uhrig Dynamical Decoupling (UDD) sequence in a variety of noise environments. Our qubit system consists of a crystalline array of $^{9}$Be$^{+}$ ions confined in a Penning trap. We use an electron-spin-flip transition as our qubit manifold and drive qubit rotations using a 124 GHz microwave system. We...

We present a study of dynamical decoupling schemes for the suppression of phase errors from various noise environments using ions in a Penning trap as a model ensemble of qubits. By injecting frequency noise we demonstrate that in an ohmic noise spectrum with a sharp, high-frequency cutoff the recently proposed UDD decoupling sequence gives noise s...

We present experimental measurements on a model quantum system that demonstrate our ability to dramatically suppress qubit error rates by the application of optimized dynamical decoupling pulse sequences in a variety of experimentally relevant noise environments. We provide the first demonstration of an analytically derived pulse sequence developed...

I will discuss progress at NIST towards scaling up ion-trap quantum information processing. This will include developments in segmented trap microfabrication, sympathetic cooling, and new methods for reducing the complexity of control fields.

The record of atomic clock frequency comparisons at NIST over the past half-decade provides one of the tightest constraints of any present-day temporal variations of the fundamental constants. Notably, the 6-year record of increasingly precise measurements of the absolute frequency of the Hg+ single-ion optical clock (using the cesium primary frequ...

We compare the frequencies of two single ion frequency standards: 27Al+ and 199Hg+. Systematic fractional frequency uncertainties of both standards are below 10-16, and the statistical measurement uncertainty is below 5 × 10-17. Recent ratio measurements show a reproducibility that is better than 10-16.

Time has always had a special status in physics because of its fundamental role in specifying the regularities of nature and because of the extraordinary precision with which it can be measured. This precision enables tests of fundamental physics and cosmology, as well as practical applications such as satellite navigation. Recently, a regime of op...

We report the technical aspects of the optical-to-microwave comparison for our recent measurements of the optical frequency of the mercury single-ion frequency standard in terms of the SI second as realized by the NIST-F1 cesium fountain clock. Over the course of six years, these measurements have resulted in a determination of the mercury single-i...

Single-trapped-ion frequency standards based on a 282 nm transition in 199 Hg + and on a 267 nm transition in 27 Al + have been developed at NIST over the past several years. Their frequencies are measured relative to each other and to the NIST primary frequency standard, the NIST-F1 cesium fountain, by means of a self-referenced femtosecond laser...

We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence det...

We investigate the temporal dynamics of Doppler cooling of an initially hot single trapped atom in the weak binding regime using a semiclassical approach. We develop an analytical model for the simplest case of a single vibrational mode for a harmonic trap, and show how this model allows us to estimate the initial energy of the trapped particle by...

We report tests of local position invariance (LPI) and constancy of fundamental constants from measurements of the frequency ratio of the 282-nm ¹⁹⁹Hg⁺ optical clock transition to the ground-state hyperfine splitting in ¹³³Cs. Analysis of the frequency ratio, extending over six years at NIST, is used to place a limi...

Recent theoretical advances have identified several computational algorithms that can be implemented utilizing quantum information processing (QIP), which gives an exponential speedup over the corresponding (known) algorithms on conventional computers. QIP makes use of the counter-intuitive properties of quantum mechanics, such as entanglement and...

Atomic ions in interconnected traps represent a potentially scalable approach to quantum information processing. Scaling the system to many qubits while minimizing errors requires extremely challenging technological improvements, but no fundamental roadblocks are currently foreseen.

Surface-electrode ion traps ootnotetextJ. Chiaverini et al., Quantum Inf. Comput. 5, 419 (2005).^, ootnotetextS. Seidelin et al., Phys. Rev. Lett. 96, 253003 (2006). are promising candidates for the large scale multi-zone ion traps which are required for large scale quantum information processing. Electrode design for surface-electrode traps is com...

We summarize initial progress towards making spin squeezed states with ˜100 ^9Be^+ ions in a Penning-Malmberg trap. We use the ground-state electron spin-flip transition, which in the 4.5 T trap magnetic field has a 124 GHz transition frequency, as the ion qubit. With a 30 mW Gunn diode oscillator we have observed pi-times as short as 100 mus. We h...

We report, for the first time, laser spectroscopy of the {sup 1}S{sub 0}{yields}{sup 3}P{sub 0} clock transition in {sup 27}Al{sup +}. A single aluminum ion and a single beryllium ion are simultaneously confined in a linear Paul trap, coupled by their mutual Coulomb repulsion. This coupling allows the beryllium ion to sympathetically cool the alumi...

We describe plans and summarize initial progress towards making spin squeezed states with up to ˜100 ^9Be^+ ions in a Penning-Malmberg trap. We use the ground-state electron spin-flip transition, which in the 4.5 T magnetic field of the trap has a transition frequency of 124 GHz, as the ion qubit. With a 30 mW Gunn diode oscillator we have observed...

We discuss the experimental characterization of several scalable ion trap architectures for quantum information processing. We have developed an apparatus for testing planar ion trap chips which features: a standardized chip carrier for ease of interchanging traps, a single-laser Raman cooling scheme, and photo-ionization loading of Mg^+ ions. The...

In a linear r.f. Paul trap, ‘crystallized’ structures of laser-cooled 199Hg+ ions are observed. The ground-state hyperfine transition at 40·5 GHz is observed in microwave-optical double-resonance spectroscopy. Future prospects are also discussed.

We have used stored ion methods to improve resolution and sensitivity in optical spectroscopy. Single atomic ions have been confined by electric and magnetic fields, cooled by laser radiation pressure to temperatures on the order of 1 mK, and probed spectroscopically with narrowband lasers. The absorption resonance of a single Hg+ ion has been obse...

We report tests of local position invariance and the variation of fundamental constants from measurements of the frequency ratio of the 282-nm 199Hg+ optical clock transition to the ground state hyperfine splitting in 133Cs. Analysis of the frequency ratio of the two clocks, extending over 6 yr at NIST, is used to place a limit on its fractional va...

As of October 2006, there were approximately 535 citations to the seminal 1977 paper of Misra and Sudarshan that pointed out the quantum Zeno paradox (more often called the quantum Zeno effect). In simple terms, the quantum Zeno effect refers to a slowing down of the evolution of a quantum state in the limit that the state is observed continuously....

Quantum mechanical effects which are manifested in measurements on trapped atomic ions are reviewed. Observation of these effects is facilitated by the long storage times of a fixed number of laser-cooled ions and by high detection sensitivities, primarily through the observation of scattered laser light. We discuss the observation of quantum jumps...

In many experiments utilizing ion traps, the ions must be cooled in order to increase the precision and accuracy of the measurements. Laser cooling is very effective when it can be applied, but it can only be used with a few kinds of ions, since it depends critically on the details of the electronic level structure. Other methods, such as resistive...

Experimental work which uses laser-cooled ions in Penning traps is reviewed. With laser-cooling the ions are strongly coupled and exhibit spatial correlations characteristic of a liquid or crystal. In plasmas with dimensions less than 10–15 interparticle spacings, the observed correlations are strongly affected by the finite size and shape of the t...

We describe the characterization of several microfabricated ion trap architectures for quantum computation. Our apparatus for testing planar ion trap chips features: a standardized chip carrier for ease of interchanging traps, a single-laser Raman sideband-cooling scheme, and photo-ionization loading of Mg^+ ions. We measure the heating rate of an...

The differential polarizability, due to near-infrared light at 1126 nm, of the 27Al+ 1S0 -> 3P0 clock transition is measured to be 4\pi\epsilon_0 x (1.6 +/- 0.5) x 10^{-31} m^3. This measurement is combined with experimental oscillator strengths to extrapolate the differential static polarizability of the clock transition as 4\pi\epsilon_0 x (1.5 +...

The basic requirements for quantum computing and quantum simulation (single- and multi-qubit gates, long memory times, etc.) have been demonstrated in separate experiments on trapped ions. Construction of a large-scale information processor will require synthesis of these elements and implementation of high-fidelity operations on a very large numbe...

We analyze the error in trapped-ion, hyperfine qubit, quantum gates due to spontaneous scattering of photons from the gate laser beams. We investigate single-qubit rotations that are based on stimulated Raman transitions and two-qubit entangling phase-gates that are based on spin-dependent optical dipole forces. This error is compared between diffe...

The electrostatic modes of a cloud of ions confined in a Penning trap are discussed in the limit that the Debye length is small compared to the cloud dimensions and the cloud dimensions are small compared to the trap dimensions. Experimental measurements of some of these mode frequencies on plasmas of laser-cooled Be+ ions agree well with calculati...

For the past 50 years, atomic standards based on the frequency of the cesium ground-state hyperfine transition have been the most accurate time pieces in the world. We now report a comparison between the cesium fountain standard NIST-F1, which has been evaluated with an inaccuracy of about 4 x 10(-16), and an optical frequency standard based on an...