Journal De Physique Lettres最新文献_第10页

High-field magnetoresistance and quantum effects in the organic compound (TMTSF)2PF6 有机化合物(TMTSF)2PF6的高场磁阻和量子效应

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046012053500

J. Ulmet, P. Auban, A. Khmou, S. Askénazy, A. Moradpour

{"title":"High-field magnetoresistance and quantum effects in the organic compound (TMTSF)2PF6","authors":"J. Ulmet, P. Auban, A. Khmou, S. Askénazy, A. Moradpour","doi":"10.1051/JPHYSLET:019850046012053500","DOIUrl":"https://doi.org/10.1051/JPHYSLET:019850046012053500","url":null,"abstract":"The transverse magnetoresistance of (TMTSF) 2 PF 6 has been investigated in magnetic field up to 32 T, at low temperatures down to 4.2 K. Shubnikov-de Haas oscillations are directly observed on the magnetoresitance in fields higher than 18 T, but there is no evidence of a threshold field since the disappearance of oscillations can be explained by the normal field-dependent damping. However these oscillations vanish very quickly between 5 and 4.2 K. This unusual behaviour could be related to a phase-transition. Finally an exploration of the fundamental field versus θ is given (θ=angle between B and c * ), showing the warping of the «Fermi tubes» along the c * axis Etude experimentale de la magnetoresistance transverse dans des champs magnetiques allant jusqu'a 32 T, a basse temperature jusqu'a 4,2 K. Observation directe d'oscillations de Shubnikov-de Haas pour des champs superieurs a 18 T, sans qu'il soit certain qu'il existe un champ seuil, la disparition des oscillations pouvant s'expliquer par l'amortissement normal fonction du champ magnetique. Disparition rapide des oscillations entre 5 et 4,2 K, peut-etre due a une transition de phase. Exploration du champ fondamental en fonction de θ (angle entre B et axe c): gondolement des «tubes de Fermi» le long de c *","PeriodicalId":14822,"journal":{"name":"Journal De Physique Lettres","volume":"52 1","pages":"535-542"},"PeriodicalIF":0.0,"publicationDate":"1985-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83964740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 39

Stretched exponential relaxation in systems with random free energies 随机自由能系统中的拉伸指数弛豫

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046011046300

C. Dominicis, H. Orland, F. Lainée

{"title":"Stretched exponential relaxation in systems with random free energies","authors":"C. Dominicis, H. Orland, F. Lainée","doi":"10.1051/JPHYSLET:019850046011046300","DOIUrl":"https://doi.org/10.1051/JPHYSLET:019850046011046300","url":null,"abstract":"A spin glass phase is characterized by a large number of quasi degenerate states (or walley bottoms). Their free energies F a =F o +f a , where f a is a non extensive fluctuation, have recently been shown to be random independent variables, as in Derrida's model. Relaxation to equilibrium of such systems is considered and a simple approximation to the transition probability (in the master equation) is considered that leads to a (random) relaxation time τ∼expβΔF with −β(F o +ΔF)= In a Σexp(−βF a ). The ensuing relaxation to equilibrium is shown to be a stretched exponential a behaviour common to a wide class of materials. The dependence of the result on the particular choice of the transition probability is touched upon Etude des verres de spin, caracterises par un grand nombre d'etats (ou fonds de vallees) quasi degeneres, d'energies libres F a =F o +f a (ou fa est une fluctuation non extensive) se comportant en variables aleatoires independantes comme dans le modele de Derrida. Analyse de la relaxation vers l'equilibre a l'aide d'une approximation simple pour la probabilite de transition (dans l'equation maitresse) qui conduit a un temps de relaxation aleatoire τ∼exp βΔF[F o +ΔF)=log a Σexp(−βF a )","PeriodicalId":14822,"journal":{"name":"Journal De Physique Lettres","volume":"2000 1","pages":"463-466"},"PeriodicalIF":0.0,"publicationDate":"1985-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86225534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 70

Pseudo-lamellar ordering in uniaxial and biaxial lyotropic nematics : a synchrotron X-ray diffraction experiment 单轴和双轴溶向线中的伪片层有序:同步加速器x射线衍射实验

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046011049900

A. M. F. Neto, Y. Galerne, A. Levelut, L. Liebert

{"title":"Pseudo-lamellar ordering in uniaxial and biaxial lyotropic nematics : a synchrotron X-ray diffraction experiment","authors":"A. M. F. Neto, Y. Galerne, A. Levelut, L. Liebert","doi":"10.1051/JPHYSLET:019850046011049900","DOIUrl":"https://doi.org/10.1051/JPHYSLET:019850046011049900","url":null,"abstract":"Synchrtron X-ray measurements are performed in both uniaxial (discotic and calamitic) and biaxial nematic lyomesophases of the mixture K-laurate, 1-decanol and D 2 O. A first-order band and a second-order band with spacing ratio 1:2 characteristic of a pseudo-lamellar structure are observed in the three nematic phases. The X-ray diffraction results are interpreted in terms of the orientational fluctuations of intrinsically biaxial correlation volumes. It is argued that the calamitic and discotic phases are not built up of cylindric-like and disk-like micelles, but of aggrgates of statistically biaxial shape, similar in the three nematic phases. The only change at the uniaxial-biaxial nematic transitions is the long-range order Mesures realisees sur un melange de laurate de potassium, decanol-1 et D 2 O. Dans les trois phases discotiques, calomitiques et biaxes, on observe le premier et le second ordre d'une bande de diffraction caracteristique d'une structure pseudo-lamellaire. Les phases calomitiques et discotiques sont composees d'agregats de forme statistiquement biaxe, seul l'ordre a longue distance change aux transitions uniaxes-biaxes","PeriodicalId":14822,"journal":{"name":"Journal De Physique Lettres","volume":"74 1","pages":"499-505"},"PeriodicalIF":0.0,"publicationDate":"1985-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79858094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 70

Relaxation rate distribution and decay profile : one fracton emission 弛豫率分布和衰减曲线:一分式发射

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046012054900

S. Alexander, O. Entin-Wohlman, R. Orbach

引用次数: 12

Pores and their number in bilayer lipid membranes 双层脂质膜上的孔及其数量

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046011051300

I. Bivas

引用次数: 6

Evidence of capillary hyperdiffusion in two-phase fluid flows 两相流体流动中毛细管超扩散的证据

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046011046700

J. Bacri, C. Leygnac, D. Salin

引用次数: 32

The singularity structure of fixed cycle directed site animals 固定周期定向位点动物的奇异结构

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046012052300

J. Duarte

引用次数: 11

Defected structural modulation in the charge density wave compounds 1T-TaS2 and 1T-TaSe2 电荷密度波化合物1T-TaS2和1T-TaSe2的结构调制缺陷

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046011050700

G. Salvetti, C. Roucau, R. Ayroles, H. Mutka, P. Molinié

引用次数: 5

Topological instability of magnetic fluids 磁流体的拓扑不稳定性

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046011048300

B. Berkovsky, V. Kalikmanov

引用次数: 13

Instability of polymer films 聚合物薄膜的不稳定性

Journal De Physique Lettres Pub Date : 1985-06-01 DOI: 10.1051/JPHYSLET:019850046012054300

A. Halperin, P. Pincus, S. Alexander

引用次数: 5