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1.
Phys Rev Lett ; 127(6): 069902, 2021 Aug 06.
Article in English | MEDLINE | ID: mdl-34420355

ABSTRACT

This corrects the article DOI: 10.1103/PhysRevLett.116.217201.

2.
Phys Rev Lett ; 121(2): 023601, 2018 Jul 13.
Article in English | MEDLINE | ID: mdl-30085738

ABSTRACT

Statistical mechanics underlies our understanding of macroscopic quantum systems. It is based on the assumption that out-of-equilibrium systems rapidly approach their equilibrium states, forgetting any information about their microscopic initial conditions. This fundamental paradigm is challenged by disordered systems, in which a slowdown or even absence of thermalization is expected. We report the observation of critical thermalization in a three dimensional ensemble of ∼10^{6} electronic spins coupled via dipolar interactions. By controlling the spin states of nitrogen vacancy color centers in diamond, we observe slow, subexponential relaxation dynamics and identify a regime of power-law decay with disorder-dependent exponents; this behavior is modified at late times owing to many-body interactions. These observations are quantitatively explained by a resonance counting theory that incorporates the effects of both disorder and interactions.

3.
Nat Mater ; 17(4): 313-317, 2018 04.
Article in English | MEDLINE | ID: mdl-29434307

ABSTRACT

Longitudinal relaxation is the process by which an excited spin ensemble decays into its thermal equilibrium with the environment. In solid-state spin systems, relaxation into the phonon bath usually dominates over the coupling to the electromagnetic vacuum1-9. In the quantum limit, the spin lifetime is determined by phononic vacuum fluctuations 10 . However, this limit was not observed in previous studies due to thermal phonon contributions11-13 or phonon-bottleneck processes10, 14,15. Here we use a dispersive detection scheme16,17 based on cavity quantum electrodynamics18-21 to observe this quantum limit of spin relaxation of the negatively charged nitrogen vacancy (NV-) centre 22 in diamond. Diamond possesses high thermal conductivity even at low temperatures 23 , which eliminates phonon-bottleneck processes. We observe exceptionally long longitudinal relaxation times T1 of up to 8 h. To understand the fundamental mechanism of spin-phonon coupling in this system we develop a theoretical model and calculate the relaxation time ab initio. The calculations confirm that the low phononic density of states at the NV- transition frequency enables the spin polarization to survive over macroscopic timescales.

4.
Phys Rev Lett ; 116(21): 217201, 2016 May 27.
Article in English | MEDLINE | ID: mdl-27284670

ABSTRACT

A hidden order that emerges in the frustrated pyrochlore Tb_{2+x}Ti_{2-x}O_{7+y} with T_{c}=0.53 K is studied using specific heat, magnetization, and neutron scattering experiments on a high-quality single crystal. Semiquantitative analyses based on a pseudospin-1/2 Hamiltonian for ionic non-Kramers magnetic doublets demonstrate that it is an ordered state of electric quadrupole moments. The elusive spin liquid state of the nominal Tb_{2}Ti_{2}O_{7} is most likely a U(1) quantum spin-liquid state.

5.
Phys Rev Lett ; 110(24): 240501, 2013 Jun 14.
Article in English | MEDLINE | ID: mdl-25165901

ABSTRACT

Quantum adiabatic passages can be greatly accelerated by a suitable control field, called a counter-diabatic field, which varies during the scan through resonance. Here, we implement this technique on the electron spin of a single nitrogen-vacancy center in diamond. We demonstrate two versions of this scheme. The first follows closely the procedure originally proposed by Demirplak and Rice [J. Phys. Chem. A 107, 9937 (2003)]. In the second scheme, we use a control field whose amplitude is constant but whose phase varies with time. This version, which we call the rapid-scan approach, allows an even faster passage through resonance and therefore makes it applicable also for systems with shorter decoherence times.

6.
Phys Rev Lett ; 107(22): 220501, 2011 Nov 25.
Article in English | MEDLINE | ID: mdl-22182018

ABSTRACT

We report the experimental realization of a hybrid quantum circuit combining a superconducting qubit and an ensemble of electronic spins. The qubit, of the transmon type, is coherently coupled to the spin ensemble consisting of nitrogen-vacancy centers in a diamond crystal via a frequency-tunable superconducting resonator acting as a quantum bus. Using this circuit, we prepare a superposition of the qubit states that we store into collective excitations of the spin ensemble and retrieve back into the qubit later on. These results constitute a proof of concept of spin-ensemble based quantum memory for superconducting qubits.

7.
Phys Rev Lett ; 106(21): 217204, 2011 May 27.
Article in English | MEDLINE | ID: mdl-21699337

ABSTRACT

We uncover a strong anisotropy in both the anomalous Hall effect (AHE) and the magnetoresistance of the chiral spin states of Pr(2)Ir(2)O(7). The AHE appearing below 1.5 K at a zero magnetic field shows hysteresis which is most pronounced for fields cycled along the [111] direction. This hysteresis is compatible with the field-induced growth of domains composed by the 3-in 1-out spin states which remain coexisting with the 2-in 2-out spin ice manifold once the field is removed. Only for fields applied along the [111] direction, we observe a large positive magnetoresistance and Shubnikov-de Haas oscillations above a metamagnetic critical field. These observations suggest the reconstruction of the electronic structure of the conduction electrons by the field-induced spin texture.

8.
Phys Rev Lett ; 100(10): 106601, 2008 Mar 14.
Article in English | MEDLINE | ID: mdl-18352216

ABSTRACT

The transverse thermoelectric (Nernst) effect on pyrochlore molybdates is investigated experimentally. In Nd(2)Mo(2)O(7) and Sm(2)Mo(2)O(7) with the spin chirality, the Nernst signal, which mostly arises from the transverse heat current (or equivalently the transverse Peltier coefficient alpha(xy)), shows a low-temperature (20-30 K) positive extremum, whereas it is absent in (Gd(0.95)Ca(0.05))(2)Mo(2)O(7) with no single-spin anisotropy of the rare-earth ion and hence with no spin chirality. The correlation between the Hall conductivity sigma(xy) and alpha(xy) in Nd(2)Mo(2)O(7) also indicates the spin chirality plays a significant role in the spontaneous (anomalous) Nernst effect.

9.
Mol Genet Genomics ; 279(3): 255-66, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18157676

ABSTRACT

The Waxy (Wx) gene product controls the formation of a straight chain polymer of amylose in the starch pathway. Dominance/recessiveness of the Wx allele is associated with amylose content, leading to non-waxy/waxy phenotypes. For a total of 113 foxtail millet accessions, agronomic traits and the molecular differences of the Wx gene were surveyed to evaluate genetic diversities. Molecular types were associated with phenotypes determined by four specific primer sets (non-waxy, Type I; low amylose, Type VI; waxy, Type IV or V). Additionally, the insertion of transposable element in waxy was confirmed by ex1/TSI2R, TSI2F/ex2, ex2int2/TSI7R and TSI7F/ex4r. Seventeen single nucleotide polymorphims (SNPs) were observed from non-coding regions, while three SNPs from coding regions were non-synonymous. Interestingly, the phenotype of No. 88 was still non-waxy, although seven nucleotides (AATTGGT) insertion at 2,993 bp led to 78 amino acids shorter. The rapid decline of r (2) in the sequenced region (exon 1-intron 1-exon 2) suggested a low level of linkage disequilibrium and limited haplotype structure. K (s) values and estimation of evolutionary events indicate early divergence of S. italica among cereal crops. This study suggested the Wx gene was one of the targets in the selection process during domestication.


Subject(s)
Genes, Plant , Plant Proteins/genetics , Setaria Plant/genetics , Starch Synthase/genetics , Alleles , Amino Acid Sequence , Amylose/metabolism , Base Sequence , DNA Primers/genetics , DNA, Plant/genetics , Evolution, Molecular , Genetic Variation , Haplotypes , Linkage Disequilibrium , Molecular Sequence Data , Phenotype , Phylogeny , Plant Proteins/metabolism , Polymerase Chain Reaction , Polymorphism, Single Nucleotide , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid , Setaria Plant/metabolism , Starch Synthase/metabolism
10.
Phys Rev Lett ; 99(8): 086602, 2007 Aug 24.
Article in English | MEDLINE | ID: mdl-17930968

ABSTRACT

The anomalous Hall effect (AHE) and anomalous Nernst effect (ANE) are experimentally investigated in a variety of ferromagnetic metals including pure transition metals, oxides, and chalcogenides, whose resistivities range over 5 orders of magnitude. For these ferromagnets, the transverse conductivity sigma{xy} versus the longitudinal conductivity sigma{xx} shows a crossover behavior with three distinct regimes in accordance qualitatively with a recent unified theory of the intrinsic and extrinsic AHE. We also found that the transverse Peltier coefficient alpha{xy} for the ANE obeys the Mott rule. These results offer a coherent and semiquantitative understanding of the AHE and ANE to an issue of controversy for many decades.


Subject(s)
Magnets
11.
Phys Rev Lett ; 98(5): 057203, 2007 Feb 02.
Article in English | MEDLINE | ID: mdl-17358893

ABSTRACT

We have investigated the Hall effect in the geometrically frustrated Kondo lattice Pr2Ir2O7. In its spin-liquid-like paramagnetic regime, the Hall resistivity rho(xy) is found to increase logarithmically on cooling. Moreover, in this low temperature region, the field dependence of the Hall conductivity sigma(xy) shows a large enhancement up to 30 Omega(-1) cm(-1) as well as a nonmonotonic change with the magnetization. Our results are far different from the anomalous Hall effect due to the spin-orbit coupling observed in ordinary magnetic conductors. We discuss the possible spin-chirality effect in the Ir 5d conduction band due to the noncoplanar texture of Pr<111> Ising-like moments.

12.
Phys Rev Lett ; 97(7): 077203, 2006 Aug 18.
Article in English | MEDLINE | ID: mdl-17026270

ABSTRACT

We report on the in-plane anisotropy of the electronic response in the spin-, charge-, and orbital-ordered phase of a half-doped layered-structure manganite. The optical conductivity spectra for a single domain of Eu1/2Ca3/2MnO4 unambiguously show the anisotropic charge dynamics which well corresponds to the theoretical calculation: the optical conductivity with the polarization along the zigzag ferromagnetic chain direction exhibits a smaller gap and a larger intensity at lower energies than that of the perpendicular polarization mostly due to the charge and orbital ordering and the associated quantum interference effect.

13.
Phys Rev Lett ; 94(7): 076405, 2005 Feb 25.
Article in English | MEDLINE | ID: mdl-15783836

ABSTRACT

The d electron orbital is a hidden but important degree of freedom controlling novel properties of transition-metal oxides. A one-dimensional orbital system is especially intriguing due to its enhanced quantum fluctuation. We present a combined experimental and theoretical study on the Raman scattering spectra in perovskite oxides NdVO(3) and LaVO(3) to prove that the quasi-one-dimensional orbital chain described by fermionic pseudospinons bears orbital excitations exchanging occupied orbital states on the neighboring sites, termed a two-orbiton in analogy with two-magnon.

14.
Histol Histopathol ; 18(4): 1155-68, 2003 10.
Article in English | MEDLINE | ID: mdl-12973684

ABSTRACT

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS), which is often associated with fatal infectious mononucleosis or T-cell lymphoproliferative diseases (LPD), is a distinct disease characterized by high mortality. Treatment of patients with EBV-AHS has proved challenging. To develop some therapeutic interventions for EBV-AHS, we examined the effectiveness of an antiviral agent (vidarabine) or chemotherapy (CHOP), using a rabbit model for EBV-AHS. Fourteen untreated rabbits were inoculated intravenously with cell-free virions of the EBV-like virus Herpesvirus papio (HVP). All of the rabbits died of HVP-associated (LPD) and hemophagocytic syndrome (HPS) between 21 and 31 days after inoculation. Furthermore, three HVP-infected rabbits treated with vidarabine died between days 23 and 28 after inoculation, and their clinicopathological features were no different from those of untreated rabbits, indicating that this drug is not effective at all to treat HVP-induced rabbit LPD and HPS. Three of the infected rabbits that were treated with one course, with an incomplete set of three courses, or with three full courses of CHOP treatment died of HVP-induced LPD and HPS with a bleeding tendency and/or with opportunistic infections. They died on the 26th, 62nd and 105th day after virus inoculation, respectively. CHOP treatment transiently suppressed the HVP-induced LPD and contributed to the prolonged survival time of two infected rabbits. However, it did not remove all of the HVP-infected cells from the infected rabbits, and residual HVP-infected lymphocytes caused recurrences of rabbit LPD and HPS. The most interesting finding of this experiment was observed in the infected rabbit with the longest survival time of 105 days: HVP-negative lymphomas surrounded by HVP-induced LPD developed in the larynx and ileum of this rabbit, causing an obstruction of the lumen. We concluded that these were not secondary lymphomas caused by CHOP treatment, because no suspicious lesions were detected in three uninfected rabbits that were treated with three courses of CHOP for 120 days. It is therefore necessary to clarify the mechanism by which HVP-negative lymphomas associated with HVP-induced LPD can develop. Our data from therapeutic trials using EBV-AHS animal models indicate that vidarabine is not effective as an agent to treat HVP-infected rabbits, and even the cytotoxic chemotherapy of CHOP is not sufficient to cure the HVP-infected rabbits or to prolong the survival time of infected rabbits. Further studies will therefore be required to develop better therapies to treat EBV-AHS.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antiviral Agents/therapeutic use , Epstein-Barr Virus Infections/drug therapy , Epstein-Barr Virus Infections/pathology , Herpes Simplex/pathology , Histiocytosis, Non-Langerhans-Cell/drug therapy , Histiocytosis, Non-Langerhans-Cell/pathology , Lymphoma/drug therapy , Lymphoproliferative Disorders/pathology , Simplexvirus , Vidarabine/therapeutic use , Animals , Antibodies, Viral/biosynthesis , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Cell Line , Cyclophosphamide/administration & dosage , Doxorubicin/administration & dosage , Genome, Viral , Herpes Simplex/virology , Humans , Immunoglobulin G/biosynthesis , Lymphoma/pathology , Lymphoma/virology , Lymphoproliferative Disorders/virology , Papio , Phenotype , Prednisone/administration & dosage , Rabbits , Reverse Transcriptase Polymerase Chain Reaction , Simplexvirus/genetics , Survival Analysis , Vincristine/administration & dosage
15.
Am J Pathol ; 158(4): 1533-42, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11290571

ABSTRACT

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis. However, the animal model for EBV-AHS has not been developed. We reported the first animal model for EBV-AHS using rabbits infected with EBV-related herpesvirus of baboon (HVP). Eleven of 13 (85%) rabbits inoculated intravenously with HVP-producing cells developed fatal lymphoproliferative disorders (LPD) between 22 and 105 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in nine of these 11 rabbits. The peroral spray of cell-free HVP induced the virus infection with increased anti-EBV-viral capsid antigen-IgG titers in three of five rabbits, and two of these three infected rabbits died of LPD with HPS. Autopsy revealed hepatosplenomegaly and swollen lymph nodes. Atypical lymphoid T cells expressing EBV-encoded small RNA-1 infiltrated diffusely in many organs, frequently involving the lymph nodes, spleen, and liver. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by polymerase chain reaction or Southern blot analysis. Reverse transcriptase-polymerase chain reaction revealed both HVP-EBNA1 and HVP-EBNA2 transcripts, suggesting latency type III infection. These data indicate that the high rate of rabbit LPD with HPS induction is caused by HVP. This system is useful for studying the pathogenesis, prevention, and treatment of human EBV-AHS.


Subject(s)
Epstein-Barr Virus Infections/complications , Herpesviridae Infections/complications , Herpesvirus 1, Cercopithecine , Histiocytosis, Non-Langerhans-Cell/virology , Lymphoproliferative Disorders/virology , Animals , Antibodies, Viral/analysis , Cell Line , Disease Models, Animal , Genome, Viral , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/immunology , Humans , Immunophenotyping , Lymphoproliferative Disorders/immunology , Lymphoproliferative Disorders/mortality , Lymphoproliferative Disorders/pathology , Papio , Rabbits
16.
Nippon Ganka Gakkai Zasshi ; 101(9): 711-7, 1997 Sep.
Article in Japanese | MEDLINE | ID: mdl-9311230

ABSTRACT

We report 2 cases of multifocal choroiditis associated with subretinal fibrosis on whom the fluorescein fundus angiography (FAG) and the indocyanine green infrared angiography (IA) were performed. Case 1 was a moderately myopic 14-year-old girl who had no ocular symptoms. She had numerous small, round, discrete, partially conflued lesions with subretinal fibrosis scattered in the periphery and one discrete relatively large lesion along the superotemporal arcade in her left fundus. Subretinal fibrosis had progressed in the superior lesion. Some lesions had coalesced into a sword-like pattern over a period of 2 years. Case 2 was a high myopic 18-year-old man who had distorted vision in his right eye. He had some small whitish round lesions with one small choroidal neovascular tissue and subretinal fibrosis in the posterior pole and a sword-like lesion in the inferior periphery. Another choroidal neovascular tissue developed near the macula during the 6-month follow-up period. In FAG, the centers of the lesions hypofluoresced corresponding to the pigmentation and the edges hyperfluoresced. Some of the lesions showed window-defects and others tissue-staining. In IA, all the whole lesions hypofluoresced from an early stage of the angiography and some major choroidal vessels were visible through them. The hypofluorescent areas persisted into the late phase. The hypofluorescent areas of the IA were larger than those seen in FAG and in funduscopy. These findings indicate that the choriocapillaris was initially damaged and consequently the structures of the lesions partly disappeared at the level of the retinal pigment epithelium-choriocapillaris complex.


Subject(s)
Choroiditis/pathology , Adolescent , Choroid/pathology , Female , Fibrosis , Fluorescein Angiography , Fundus Oculi , Humans , Male , Neovascularization, Pathologic , Retina/pathology
17.
Nihon Geka Gakkai Zasshi ; 94(5): 456-65, 1993 May.
Article in Japanese | MEDLINE | ID: mdl-8332120

ABSTRACT

In view of the operative field of esophageal cancer, anatomic findings of the bronchial arteries were studied in specimens of 38 cadavers. The number of right and left bronchial arteries were 68 and 61, respectively. The most common branching type was two right and two left arteries, occurring in 36.8% (14/38). Next common type was two right and one left arteries (34.2%). Each specimen had one right intercostobronchial artery and it was considered easy to preserve blood supply to right bronchial artery when cleansing of mediastinal lymphatic chain is performed. But the other 30 right bronchial arteries originating from the aorta coursed, to the area of inferior tracheobronchial lymph nodes, and thus there will be possibility of injury. All of the left bronchial arteries derived from the aorta. The course of 5 left bronchial arteries ran to the area of inferior tracheobronchial lymph nodes, and the one of 41 arteries passed to the area of left tracheobronchial lymph nodes. Therefore, there will be strong possibility of injury to these left bronchial arteries. But the other 19 left bronchial arteries didn't course to any area of lymph nodes, and the arteries can possibly be preserved.


Subject(s)
Bronchial Arteries/anatomy & histology , Esophageal Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Female , Humans , Lymph Node Excision , Lymph Nodes/blood supply , Male , Middle Aged
18.
Nihon Geka Gakkai Zasshi ; 93(4): 437-41, 1992 Apr.
Article in Japanese | MEDLINE | ID: mdl-1603050

ABSTRACT

A 23-year-old woman developed thrombosis of the superior mesenteric vein and underwent an extensive enterectomy. She was diagnosed to have ATIII deficiency with extrahepatic portal vein thrombosis and esophagogastric varices. She was admitted to our department and underwent esophageal mucosal transection and splenectomy. Her activities of ATIII were 46%, but ATIII activities of her family were over 90%. ATIII activities during perioperative period were kept more than 70% following administration of ATIII drug. After splenectomy thrombocythemia which was over 300 x 10(4)/mm3 appeared with severe headache and slight pain of hands. She was discharged on 76th postoperative day with no complications and collapse of esophageal varices.


Subject(s)
Antithrombin III Deficiency , Esophageal and Gastric Varices/surgery , Portal Vein , Thrombosis/complications , Adult , Esophageal and Gastric Varices/complications , Female , Humans , Splenectomy
19.
Jpn J Surg ; 21(4): 444-9, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1960903

ABSTRACT

We report herein a case of a 46 year old man presenting with a gastric ulcer in whom an endoscopy happened to detect an elevated lesion in the lower esophagus. Endoscopic biopsy proved sufficient for determining the diagnosis of a granular cell tumor (GCT). Electron and microscopic studies suggest that GCT are derived from Schwann cells. Although commonly found in the tongue and skin, GCT are rarely seen in the gastrointestinal tract, especially in the esophagus. However, advances in endoscopic techniques will increase the opportunity of detecting GCT of the esophagus.


Subject(s)
Esophageal Diseases , Granular Cell Tumor , Biopsy , Esophageal Diseases/complications , Esophageal Diseases/diagnosis , Esophageal Diseases/pathology , Esophagoscopy , Granular Cell Tumor/complications , Granular Cell Tumor/diagnosis , Granular Cell Tumor/pathology , Humans , Male , Middle Aged , Schwann Cells , Stomach Ulcer/complications
20.
Nihon Gan Chiryo Gakkai Shi ; 25(12): 2744-51, 1990 Dec 20.
Article in Japanese | MEDLINE | ID: mdl-2074383

ABSTRACT

Of 342 breast cancer patients radically operated on in the Second Department of Surgery, School of Medicine, Chiba University during 1965-1988, treatment for 75 recurrent patients were evaluated by the initial modes of recurrence. The modes of recurrence were classified into distant metastases, local lymph node recurrence (axillary, parasternal and supraclavicular nodes) and chest wall recurrence according to the General Rules for Clinical and Pathological Recording of Breast Cancer. Of 75 recurrent patients, distant metastases were seen as common as 77.3%, followed by recurrences of local lymph nodes (14.7%) and chest wall (8.0%). The number of patients in each mode of recurrence increased in relation to increase in the size of tumor and the number of metastatic lymph nodes at the time of the first operation. Histologically, scirrhous carcinoma was most common in chest wall recurrence. 2-year disease-free survival rates of distant metastases, local lymph node recurrence and chest wall recurrence were 44.6%, 24.2% and 16.7%, respectively. 5-year survival of bone metastasis with chemo-endocrine therapy was as significantly favorable as 60%, compared to chemo- or radiotherapy alone (p less than 0.01). However, 5-year survival of lung metastasis with or without endocrine therapy revealed no significant difference. Local lymph node recurrence with the combination of resection, radio- and/or chemotherapy produced a trend toward showing more favorable survival than that without resection.


Subject(s)
Bone Neoplasms/secondary , Breast Neoplasms/surgery , Lung Neoplasms/secondary , Bone Neoplasms/epidemiology , Bone Neoplasms/therapy , Breast Neoplasms/epidemiology , Breast Neoplasms/pathology , Female , Follow-Up Studies , Humans , Japan/epidemiology , Lung Neoplasms/epidemiology , Lung Neoplasms/therapy , Lymphatic Metastasis
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