Bulletin of the American Physical Society
APS March Meeting 2020
Volume 65, Number 1
Monday–Friday, March 2–6, 2020; Denver, Colorado
Session W67: Strange Metal PhysicsInvited
|
Hide Abstracts |
Sponsoring Units: DCMP Chair: Manuel Zingl Room: Four Seasons 2-3 |
Friday, March 6, 2020 8:00AM - 8:36AM |
W67.00001: Theories of Planckian dissipation in strongly correlated systems Invited Speaker: Aavishkar Patel The apparently universal value, 2π kBT/h, of the transport scattering rate observed experimentally in a wide variety of non-Fermi liquid metals with T-linear resistivity has been a longstanding mystery in condensed matter physics; this phenomenon is called 'Planckian dissipation'. We present a lattice model of fermions with N flavors and random interactions that describes a non-Fermi liquid metal at low temperatures T → 0, in the solvable limit of large N. We begin with quasiparticles around a Fermi surface with effective mass m*, and then include random interactions that lead to fermion spectral functions with frequency scaling with 2π kBT/h. The resistivity ρ obeys the Drude formula ρ = m*/(ne2τtr), where n is the density of fermions, and the transport scattering rate is 1/τtr = f 2π kBT/h; we find f to be of order unity and essentially independent of the strength and form of the interactions, hence 'universal'. The random interactions are a generalization of the Sachdev-Ye-Kitaev models; it is assumed that processes nonresonant in the bare quasiparticle energies only renormalize m*, while resonant processes are shown to produce Planckian dissipation. We point out some predictions of this theory that are, in principle, testable in photoemission experiments. We further present some other large N models that can also give rise to Planckian dissipation under certain conditions. |
Friday, March 6, 2020 8:36AM - 9:12AM |
W67.00002: T-linear resistivity and Planckian dissipation in cuprates Invited Speaker: Anaelle Legros The perfectly linear temperature dependence of the resistivity observed as T→0 in a variety of metals close to a quantum critical point (QCP) is a major puzzle of condensed matter physics. I will present resistivity measurements supporting that T-linear resistivity as T→0 is a generic property of cuprates, associated with a universal scattering rate [1]. We measured the low-T resistivity of the bi-layer cuprate Bi2212 just above its pseudogap critical point p* and found that it exhibits a T-linear dependence with the same slope as in the single-layer cuprate Nd-LSCO close to its own p*, despite their very different Fermi surfaces and structural, superconducting and magnetic properties. We then showed that the T-linear coefficient (per CuO2 plane), noted A, for various cuprates presenting this phenomenon, is given by a universal relation implying a specific scattering rate for charge carriers in all these samples: 1/τ = h/2πkBT, where h is the Planck constant and kB is the Boltzmann constant. This specific scattering rate corresponds to what is called the Planckian limit, and works not only for hole-doped cuprates but also for electron-doped cuprates, despite the different nature of their QCP and strength of their electron correlations. |
Friday, March 6, 2020 9:12AM - 9:48AM |
W67.00003: Strange Metals and Anomalous Dimensions for Conserved Currents Invited Speaker: Philip Phillips The unsaturating resistivity exceeding the Ioffe-Regel-Mott bound in the strange metal phase of the cuprates implies that electrons are not the propagating degrees of freedom. The search for new degrees of freedom has led some to conclude that not only does the relevant gauge field that describes the interactions with electromagnetic radiation have an anomalous dimension but so does the current. This conclusion flies in the face of the well known result in quantum field theory that conserved quantities do not acquire anomalous dimensions under any amount of renormalization. My talk will focus on demistifying the claim of anomalous dimensions of conserved quantities. I will show that N\"other's Second Theorem[1,2] actually allows for electromagnetisms in which the conserved current and gauge field can actually have arbitrary dimensions. Specific models are constructed which exhibit such anomalies[1,2]. I will show that the resulting Aharonov-Bohm effect deviates strongly from the standard result and hence can be used a sharp test of anomalous dimensions in the strange metal phase of the cuprates. |
Friday, March 6, 2020 9:48AM - 10:24AM |
W67.00004: Meigan Aronson Invited Talk
|
Friday, March 6, 2020 10:24AM - 11:00AM |
W67.00005: Strange metallicity in the doped Hubbard model Invited Speaker: Thomas Devereaux Strange or bad metallic transport, defined by its incompatibility with conventional quasiparticle pictures, is a theme common to strongly correlated materials and ubiquitous in high temperature superconductors. The Hubbard model represents a minimal starting point for modeling strongly correlated systems. Here we demonstrate strange metallic transport in the doped two-dimensional Hubbard model using determinantal quantum Monte Carlo calculations. Over a wide range of doping, we observe resistivities exceeding the Mott-Ioffe-Regel limit with linear temperature dependence. The temperatures of our calculations extend to as low as 1/40 the non-interacting bandwidth, placing our findings in the degenerate regime relevant to experimental observations of strange metallicity. Our results provide a foundation for connecting theories of strange metals to models of strongly correlated materials. |
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. |
© 2024 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
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700