Bulletin of the American Physical Society
APS March Meeting 2017
Volume 62, Number 4
Monday–Friday, March 13–17, 2017; New Orleans, Louisiana
Session R41: Superconductivity: Transport Properties |
Hide Abstracts |
Sponsoring Units: DCMP Chair: Joseph Prestigiacomo, US Naval Research Laboratory Room: 388 |
Thursday, March 16, 2017 8:00AM - 8:12AM |
R41.00001: Observation of Sinusoidal Voltage Behaviour in Silver Doped YBCO Atilgan Altinkok, Murat Olutas, Kivilcim Kilic, Atilla Kilic The influence of bi-directional square wave (BSW) current was investigated on the evolution of the $V -t$ curves at different periods ($P)$, temperatures and external magnetic fields. It was observed that slow transport relaxation measurements result in regular sinusoidal voltage oscillations which were discussed mainly in terms of the dynamic competition between pinning and depinning.The symmetry in the voltage oscillations was attributed to the elastic coupling between the flux lines and the pinning centers along grain boundaries and partly inside the grains. This case was also correlated to the equality between flux entry and exit along the YBCO/Ag sample during regular oscillations. It was shown that the voltage oscillations can be described well by an empirical expression $V(t)$ \textasciitilde sin(\textit{wt}$+\varphi )$. We found that the phase angle $\varphi $generally takes different values for the repetitive oscillations. Fast Fourier Transform analysis of the $V-t$ oscillations showed that the oscillation period is comparable to that ($P_{\mathrm{I}})$ of the BSW current. This finding suggests a physical mechanism associated with charge density waves (CDWs), and, indeed, the weakly pinned flux line system in YBCO/Ag resembles the general behavior of CDWs. At certain values of $P_{\mathrm{I}}$, amplitude of BSW current, $H$ and $T$, the YBCO/Ag sample behaves like a double-integrator, since it converts the BSW current to sinusoidal voltage oscillations in time. [Preview Abstract] |
Thursday, March 16, 2017 8:12AM - 8:24AM |
R41.00002: Fermi surface reconstruction of electron-doped La$_{\mathrm{\mathbf{2-x}}}$\textbf{Ce}$_{\mathrm{\mathbf{x}}}$\textbf{CuO}$_{\mathrm{\mathbf{4}}}$\textbf{ from transport experiments} Tarapada Sarkar, Pampa Rani Mandal, Joshua Higgins, Yi Zhao, Heshan Yu, Kui Jin, Richard L. Greene We report Hall Effect, Nernst Effect, and resistivity measurements on La$_{\mathrm{2-x}}$Ce$_{\mathrm{x}}$CuO$_{\mathrm{4}}$ (LCCO) thin films as a function of doping and temperature for magnetic fields up to 14T. A change in the sign of the low temperature Hall coefficient at 2K suggests that the Fermi surface reconstructs at a critical doping of Ce$=$ 0.14. This agrees with some prior high field Hall Effect measurements of the LCCO system [\textit{K. Jin, et al. PRB 78, 174521 (2008)}]. In addition, we find a large change in the carrier number at this doping, similar to that seen in PCCO films [\textit{Y. Dagan, et al. Phys. Rev. Lett.~92, 167001~(2004)}] and hole-doped cuprates [\textit{S. Badoux, et al. Nature }\textbf{\textit{531}}\textit{, 210-214 (2016)}]. The implications of these results for quantum critical behavior in the electron-doped cuprates will be discussed. [Preview Abstract] |
Thursday, March 16, 2017 8:24AM - 8:36AM |
R41.00003: Tailoring ultra-thin 2D nanomesh superconductors with robust superfluid density and extraordinary magnetotrasport properties Hyoungdo Nam, Philip Adams, Chih-Kang Shih Uniform two-dimensional (2D) superconductors (SC) with strong spin-orbit coupling, such as Pb films, show robust superfluid rigidity and have parallel critical magnetic fields (\textasciitilde 50 T) that are much larger than Clogston-Chandrasekhar limit, as we previously reported. By tuning the epitaixial growth kinetics, we recently produced a 2D Pb nanowire network, which we term ``nanomesh''. The nanomeshes have a uniform thickness of 7ML and an average nanowire width of 40 nm. Depending on the growth conditions, the nanomesh can be tuned to be above or below percolation threshold. In-situ double-coil mutual inductance measurement shows very strong superfluid rigidity when the network is above percolation threshold but the superfluid rigidity is weakened significantly near the threshold. For 2D nanomeshes above the percolation threshold, magnetotransport measurements reveal extremely high parallel critical fields (estimated to be \textgreater 100 T) as well as an anomalous perpendicular critical field temperature dependence. In addition, Little-Parks oscillations are observed in magneto-transport measurements near Tc. [Preview Abstract] |
Thursday, March 16, 2017 8:36AM - 8:48AM |
R41.00004: Hall effect in cuprates with collinear incommensurate spin density waves Maxime Charlebois, Simon Verret, Olivier Simard, Alexandre Foley, David Sénéchal, A.-M. S. Tremblay The recently measured normal-state Hall effect in high-magnetic field shows that the carrier density drops in the pseudogap. More specifically, it scales like the doping $p$ at small $p$ and eventually raises to $1+p$ at the doping where the pseudogap appears [1]. Whether the low-doping $p$ behavior arises from spin density waves (SDWs) or from Mott physics is still an open question. Using the approach of Voruganti et al. [2], we studied the doping dependence of the Hall effect of mean-field collinear incommensurate spin-density-waves. The results are contrasted with those of antiferromagnetic [3] and incommensurate spiral spin-density waves [4]. --- [1] Badoux et al., Nature 531 210 (2016) [2] Voruganti et al., PRB 45 13945 (1992) [3] Storey, EPL 113 27003 (2016) [4] Eberlein et al., PRL 117 187001 (2016) [Preview Abstract] |
Thursday, March 16, 2017 8:48AM - 9:00AM |
R41.00005: A quantitative relationship between the Nernst effect and diamagnetism in the cuprates Subroto Mukerjee, Kingshuk Sarkar, Sumilan Banerjee, T. V. Ramakrishnan The observed Nernst effect and diamagnetism appear to be strongly related in many classes of superconductors, especially the cuprates. However a complete understanding of this relationship across the entire phase diagram of the cuprates (i.e. as a function of all accessible values of doping, temperature and magnetic field) is lacking. Here, we quantify the relationship between the two quantities in terms of a single dimensionless parameter $M/(T \alpha_{xy})$, where $M$ is the magnetization and $\alpha_{xy}$, the off-diagonal Peltier coefficient. We calculate this quantity as a function of doping, temperature and field based on a phenomenological model of the cuprates proposed by two of us that has previously produced good agreement with several experimentally measured quantities. In particular, we show that we can interpolate between the Gaussian and strongly phase fluctuating $XY$ limits of the cuprate superconductors and find agreement with previous calculations in those limits. We show that our results for the dependence of $\alpha_{xy}$ and $M/(T \alpha_{xy})$ on doping, temperature and field are in good quantitative agreement with experiments on the cuprates. [Preview Abstract] |
Thursday, March 16, 2017 9:00AM - 9:12AM |
R41.00006: Electronic structure of high-T$_{\mathrm{c}}$ cuprates revealed by high-magnetic fields Mun Chan, Eric Bauer, Ross McDonald, Neil Harrison The small reconstructed Fermi surface revealed by high-magnetic field quantum oscillation measurements in bilayer YBa$_{\mathrm{2}}$Cu$_{\mathrm{3}}$O$_{\mathrm{6+x}}$ opened a path towards identifying broken symmetry states in underdoped cuprate supercoductors. Recent quantum oscillations measurements on the structurally simpler HgBa$_{\mathrm{2}}$CuO$_{\mathrm{4+d}}$ indicate that the Fermi surface comprises only a single quasi-two dimensional pocket. These results suggests Fermi-surface reconstruction attributable to the charge-density-wave observed with other spectroscopic methods. However, the exact form of this charge-density-wave and its relationship to high-Tc superconductivity remains a pressing open question. We will present new insights into the low temperature electronic structure of the cuprates probed with electrical transport in magnetic fields up to 90T. [Preview Abstract] |
Thursday, March 16, 2017 9:12AM - 9:24AM |
R41.00007: Shubnikov-de Haas Oscillations in the Electron-doped Cuprate Superconductors J. S. Higgins, M. K. Chan, T. Sarkar, R. D. McDonald, R. L. Greene, N. P. Butch We have studied the electronic structure of electron-doped cuprate superconductors via measurements of Shubnikov-de Haas oscillations in thin films with magnetic fields up to 80 T and in temperatures from 0.7 K to 20 K. In optimally and overdoped Pr$_{\mathrm{2-x}}$Ce$_{\mathrm{x}}$CuO$_{\mathrm{4}}$ and optimally doped La$_{\mathrm{2-x}}$Ce$_{\mathrm{x}}$CuO$_{\mathrm{4}}$, quantum oscillations indicate the presence of a small Fermi surface, indicative of electronic reconstruction. These measurements show that superconductivity emerges from a similar electronic state in all of the electron-doped cuprates. We will discuss low-temperature signatures of residual magnetic fluctuations that may connect the electronic structure to the nearby quantum critical point. [Preview Abstract] |
Thursday, March 16, 2017 9:24AM - 9:36AM |
R41.00008: Isotope effect in superconducting n-doped SrTiO$_3$ Adrien Stucky, Gernot Scheerer, Zhi Ren, Didier Jaccard, Jean-Marie Poumirol, Céline Barreteau, Enrico Giannini, Dirk van der Marel Since the discovery of superconductivity in n-doped SrTiO$_3$ half a century ago, this material has played a key role in modern condensed matter physics, in part for its superconducting properties but also its dielectric properties and suitability as a substrate for thin film growth of high-T$_c$ superconductors. We report the influence on the superconducting critical temperature in doped SrTiO$_3$ of the substitution of the natural $^{16}$O atoms by the heavier isotope $^{18}$O. We have found a huge increase of the T$_c$ around $50\%$ and an enhancement by a factor $\sim 2$ of the critical magnetic field H$_{c2}$ for all charge carrier densities. Such a strong impact on T$_c$ and H$_{c2}$, with a sign opposite to conventional superconductors, is unprecedented. Alternative models which take into account the presence of polarons in SrTiO$_3$ or the vicinity of a quantum critical point due to ferroelectric state are now considered and discussed to explain this behavior. Indeed, the unusually large size of the observed isotope effect supports a recent model for superconductivity in these materials based on strong coupling to the ferroelectric soft modes of SrTiO$_3$. [Preview Abstract] |
Thursday, March 16, 2017 9:36AM - 9:48AM |
R41.00009: Superconductivity and Magnetotransport of MBE grown~Nb$_{\mathrm{2}}$N/SiC and Nb$_{\mathrm{2}}$N/AlN Heterostructures Suresh Vishwanath, Rusen Yan, Scott Katzer, Neeraj Nepal, Brian Downey, David Meyer, Guru Bahadur Singh Khalsa, John Wright, Yimo Han, David Muller, Amit Verma, Edward Lochocki, Kyle Shen, Huili Grace Xing, Debdeep Jena We find that plasma assisted molecular beam epitaxy (MBE) grown $\beta $-Nb$_{\mathrm{2}}$N thin films [1] are metallic at room temperature, and undergo an electronic phase transition to the superconducting phase below about 10K. Hall-effect measurements reveal a bulk charge density of \textasciitilde 4E23 cm$^{\mathrm{-3}}$ and a mobility of 0.4-0.9 cm$^{\mathrm{2}}$/V.s. Superconducting transition temperature Tc \textasciitilde 10K, in-plane and out of plane critical magnetic field as a function of temperature have been obtained using resistivity and vibrating sample magnetometry measurements. Using this data, an Ioffe-Regel parameter of 10-15, a coherence length of 5-12 nm, and the London penetration depth have been estimated for various thickness of high quality epitaxial Nb$_{\mathrm{2}}$N films. We will contrast transport and structural quality in MBE Nb$_{\mathrm{2}}$N with well-studied NbN by a detailed analysis of aforesaid measurements along with X-Ray diffraction and Transmission-Electron Microscopy data. [1] D.S.Katzer et al., Appl. Phys. Express 8 085501 (2015) [Preview Abstract] |
Thursday, March 16, 2017 9:48AM - 10:00AM |
R41.00010: Simulations of magnetotransport in Hg-1201 Sylvia Lewin, James Analytis The superconducting compounds HgBa$_2$Ca$_{n-1}$Cu$_n$O$_{2n+2+\delta}$ hold the distinction of having the highest transition temperatures at ambient pressure for a given number of CuO$_2$ layers (up to $n = 3$). They also have a simple tetragonal structure and have relatively little structural distortion or chemical disorder in the CuO$_2$ planes compared to other high-temperature superconductors. The simplest of these structures is HgBa$_2$CuO$_{4+\delta}$ (Hg-1201), making it an attractive model system to study. I will share simulations of magnetotransport in Hg-1201 for a variety of possible Fermi surfaces, which should help to elucidate current data and guide future experiments on this material. [Preview Abstract] |
Thursday, March 16, 2017 10:00AM - 10:12AM |
R41.00011: Pseudogap critical point inside the superconducting phase of cuprates B. MICHON, S. LI, P. BOURGEOIS-HOPE, S. BADOUX, N. DOIRON-LEYRAUD, L. TAILLEFER, J. ZHOU Recent high-field measurements of electrical transport in cuprates have revealed a new signature of the critical point p* where the pseudogap phase ends at T=0 in the absence of superconductivity: the carrier density drops abruptly from n=1+p above p* to n=p below [1,2,3]. Two questions arise: 1) Is the ground state of the pseudogap phase truly a metal, given the large upturn in the resistivity as low T, dubbed a “metal-to-insulator” crossover? 2) Is p* present inside the superconducting phase in zero field? Here we report low-temperature measurements of thermal conductivity in the cuprate superconductor Nd-LSCO for dopings across p*. We obtain the residual linear term at T=0, $\kappa_{0}/T$, as a function of magnetic field and doping. At high fields, we find that $\kappa_{0}/T$ satisfies the Wiedemann-Franz law at all dopings. This shows that the ground state of the pseudogap phase is a metal, and p* corresponds to a metal-to-metal transition at T=0. In zero field, a very similar drop in $\kappa_{0}/T$ across p* is observed, showing that p* is present in zero field inside the superconducting phase.\\\\~[1] S.~Badoux~{\it et al.}, Nature~{\bf 531},~210~(2016)\\~[2] F.~Lalibert\'e~{\it et al.}, arXiv:1606.04491~(2016)\\~[3] C.~Collignon~{\it et al.}, arXiv:1607.05693~(2016) [Preview Abstract] |
Thursday, March 16, 2017 10:12AM - 10:24AM |
R41.00012: Fermi-surface transformation across the pseudogap critical point of the cuprate superconductor Nd-LSCO C. Collignon, S. Badoux, A.S. Afshar, B. Michon, F. Laliberte, O. Cyr-Choiniere, N. Doiron-Leyraud, L. Taillefer, J.S. Zhou, S. Licciardello, S. Wiedmann |
Thursday, March 16, 2017 10:24AM - 10:36AM |
R41.00013: Abstract Withdrawn Recent measurements of the resistivity and Hall coefficient in cuprates at high magnetic fields have revealed a new signature of the critical point $p^{\star}$ where the pseudogap phase ends at $T=0$ in the absence of superconductivity: the carrier density drops abruptly from $n = 1+p$ above $p^{\star}$ to $n = p$ below [1,2,3]. \\ Here we report on our search for such a signature in the cuprate superconductor Bi2201, whose pseudogap critical point is located at $p^{\star} \simeq 0.21$, based on NMR [4] and ARPES [5] studies.\\ We report the first results of our measurements of transport coefficients in overdoped samples of Bi2201 in magnetic fields large enough to access the normal state at $T \to 0$.\\~ [1] S.~Badoux~{\it et al.}, Nature~{\bf 531},~210~(2016).\\~ [2] F.~Lalibert\’e~{\it et al.}, arXiv:1606.04491~(2016).\\~ [3] C.~Collignon~{\it et al.}, arXiv:1607.05693~(2016).\\~ [4] S.~Kawasaki~{\it et al.}, Phys.~Rev.~Lett.~{\bf 105},~137002~(2010).\\~ [5] T.~Kondo~{\it et al.}, Nat.~Phys.~{\bf 7},~21~(2011).\\ |
Thursday, March 16, 2017 10:36AM - 10:48AM |
R41.00014: Linear-T resistivity at the pseudogap critical point of the cuprate superconductor Bi2212 A. Legros, L. Taillefer, S. Benhabib, W. Tabis, B. Vignolle, D. Vignolles, C. Proust, H. Raffy, Z. Z. Li, D. Colson, A. Forget We report high-field measurements of the electrical resistivity on a highly overdoped thin film of Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ ($T_c = 50$~K), one of the archetypal cuprate superconductors, with a high maximal $T_c$ (90~K). Measurements up to 55 T enabled us to suppress superconductivity and track the normal-state behavior down to low temperature. We observe a linear temperature dependence of the resistivity as $T \to 0$, at a doping $p = 0.23$ just above $p^{\star} \simeq 0.22$, the critical doping where the pseudogap phase ends [1,2]. Our data on Bi2212 are in excellent agreement with previous data on cuprates with lower maximal $T_c$, namely LSCO [3] and Nd-LSCO [4]. This shows that a linear-$T$ resistivity is a universal signature of the pseudogap critical point in cuprates, reminiscent of the linear-$T$ resistivity found at the quantum critical point of heavy-fermion, pnictide and organic superconductors [5].\\~[1] I.~Vishik~{\it et al.}, PNAS~{\bf 109},~18332~(2012).\\~[2] S.~Benhabib~{\it et al.}, Phys.~Rev.~Lett.~{\bf 114},~147001~(2015).\\~[3] R.~A.~Cooper~{\it et al.}, Science~{\bf 323},~603~(2009).\\~[4] R.~Daou ~{\it et al.}, Nat.~Phys.~{\bf 5},~31~(2009).\\~[5] L.~Taillefer, Annu.~Rev.~Condens.~Matter Phys.~{\bf 1},~51~(2010) [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2020 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
1 Research Road, Ridge, NY 11961-2701
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700