Author(s): Guglielmo Lami, Jacopo De Nardis, and Xhek Turkeshi
We investigate quantum random tensor network states in which the dimension of the bond scales polynomially with the size of the system N. Specifically, we examine the delocalization properties of random matrix product states (RMPS) in the computational basis by deriving an exact analytical expressio…
[Phys. Rev. Lett. 134, 010401] Published Thu Jan 02, 2025
Author(s): F. Cugini, S. Chicco, F. Orlandi, G. Allodi, P. Bonfá, V. Vezzoni, O. N. Miroshkina, M. E. Gruner, L. Righi, S. Fabbrici, F. Albertini, R. De Renzi, and M. Solzi
Magnetic frustration in ferromagnetic metallic systems is unusual due to the long-range and symmetric nature of the exchange interactions. In this work we prove that it is possible to obtain a highly frustrated ferromagnetic phase in a multisublattices cubic structure through a fine-tuning of the ma…
[Phys. Rev. B 105, 174434] Published Thu May 26, 2022
Author(s): Berislav Buča
Is a spontaneous perpetual reversal of the arrow of time possible? The out-of-time-ordered correlator (OTOC) is a standard measure of irreversibility, quantum scrambling, and the arrow of time. The question may be thus formulated more precisely and conveniently: can spatially ordered perpetual OTOC ...
[Phys. Rev. Lett. 128, 100601] Published Fri Mar 11, 2022
Author(s): T. Tanaka, D. J. Hinde, M. Dasgupta, E. Williams, K. Vo-Phuoc, C. Simenel, E. C. Simpson, D. Y. Jeung, I. P. Carter, K. J. Cook, N. R. Lobanov, D. H. Luong, C. Palshetkar, D. C. Rafferty, and K. Ramachandran
Mass and angle distributions for the Cr52+Pt198 and Cr54+Pt196 reactions (both forming No250) were measured and subtracted, giving new information on fast quasifission mass evolution, and the first direct determination of the dependence of sticking times on angular momentum. TDHF calculations showed...
[Phys. Rev. Lett. 127, 222501] Published Wed Nov 24, 2021
Author(s): Yahya Alavirad and Jay Sau
We study ferromagnetism and its stability in twisted bilayer graphene. We work with a Hubbard-like interaction that corresponds to the screened Coulomb interaction in a well-defined limit where the Thomas-Fermi screening length lTF is much larger than monolayer graphene's lattice spacing lg≪lTF and ...
[Phys. Rev. B 102, 235123] Published Fri Dec 11, 2020
Author(s): Florian Katsch and Andreas Knorr
Microscopic simulations demonstrate how to optically prepare and coherently control temporal oscillations due to quantum superpositions in a gas of excitons (bound electron-hole pairs).
[Phys. Rev. X 10, 041039] Published Tue Nov 24, 2020
We studied the electronic Raman spectra of (Li$_{1-x}$Fe$_x$)OHFeSe as a function of light polarization and temperature. In the B$_{1g}$ spectra alone we observe the redistribution of spectral weight expected for a superconductor and two well-resolved peaks below T$_c$. The nearly resolution-limited peak at 110 cm$^{-1}$ (13.6 meV) is identified as a collective mode. The peak at 190 cm$^{-1}$ (23.6 meV) is presumably another collective mode since the line is symmetric and its energy is significantly below the gap energy observed by single-particle spectroscopies. Given the experimental band structure of (Li$_{1-x}$Fe$_x$)OHFeSe, the most plausible explanations include conventional spin-fluctuation pairing between the electron bands and the incipient hole band and pairing between the hybridized electron bands. The absence of gap features in A$_{1g}$ and B$_{2g}$ symmetry favors the second case. Thus, in spite of various differences between the pnictides and chalcogenides, this Letter demonstrates the proximity of pairing states and the importance of band structure effects in the Fe-based compounds.
Author(s): N. V. Leppenen, L. E. Golub, and E. L. Ivchenko
The exciton problem is solved in the two-dimensional Dirac model with allowance for strong electron-hole attraction. The exciton binding energy is assumed smaller than but comparable to the band gap. The exciton wave function is found in the momentum space as a superposition of all four two-particle...
[Phys. Rev. B 102, 155305] Published Wed Oct 21, 2020
Lightwave quantum electronics utilizes the oscillating carrier wave of intense laser fields to control quantum materials properties. Using quantum kinetic equations of motion, we describe lightwave-driven nonlinear quantum transport of electronic spin and charge with simultaneous quantum fluctuations of non-collinear local spins. During cycles of field oscillations, spin-charge inter-atomic quantum excitations trigger non-adiabatic time evolution of an antiferromagnetic insulator state into a metallic non-equilibrium state with transient magnetization. Lightwave modulation of electronic hopping changes the energy landscape and establishes a non-thermal pathway to laser-induced transitions in correlated systems with strong local magnetic exchange interactions.
Nature Communications, Published online: 28 February 2020; doi:10.1038/s41467-020-14821-z
AnnexinV has been shown to bind phosphatidylserine expressed by chemotherapy-induced apoptotic cells increasing their immunogeneicity. Here, the authors demonstrate in a preclinical tumor model that fusing tumor-antigen peptide to Annexin V enhances its efficacy when administered after chemotherapy and with other immune checkpoint inhibitors.By holographic duality, we identify a novel dynamical phase transition which results from the temperature dependence of non-equilibrium dynamics of dark solitons in a superfluid.For a non-equilibrium superfluid system with an initial density of dark solitons, there exists a critical temperature $T_d$,above which the system relaxes to equilibrium by producing sound waves, while below which it goes through an intermediate phase with a finite density of vortex-antivortex pairs. In particular, as $T_d$ is approached from below, the density of vortex pairs scales as $(T_d - T)^\gamma$ with the critical exponent $\gamma = 1/2$.
Motivated by emergent $SU(2)$ symmetry in the spin orbit coupled system, we study the spin helix driven insulating phase in two dimensional lattice. When both Rashba and Dresselhaus spin orbit couplings are present, the perfect Fermi surface nesting occurs at a special condition depending on the lattice geometry. In this case, the energies of spin up at any wave vector $\vec{k}$ are equivalent to the ones of spin down at $\vec{k}\!+\!\vec{Q}$ with so-called the \textit{shifting wave vector} $\vec{Q}$. Thus, the system stabilizes magnetic insulator with spiral like magnetic ordering even in the presence of tiny electron-electron interaction where the magnetic ordering wave vector is proportional to $\vec{Q}$. We first show the condition for existence of the \textit{shifting wave vector} in general lattice model and emergent $SU(2)$ symmetry in the spin orbit coupled system. Then, we exemplify this in square lattice at half filling and discuss the insulating phase with (non-) coplanar spin density wave and charge order. Our study emphasizes possible new types of two dimensional magnetic materials and can be applicable to various van-der Waals materials and their heterostructures with the control of electric field, strain and pressure.
We propose a novel mechanism to achieve superconductivity at zero chemical potential, within the holographic framework. Extending previous construction of the holographic superconductors, we consider an Einstein-Maxwell system coupled with two interacting scalars in Anti-de Sitter space. One of the scalar fields is charged and therefore, interacts non-trivially with the gauge field, while the other is uncharged. We find that, if we turn on a boundary source for the uncharged scalar field, it forces the condensation of the charged scalar, leading to a superconducting phase in the dual boundary theory. The condensation occurs at a certain critical value of the source, depending on the value of the chemical potential, which can even be zero. We work out the complete phase diagram of this scenario. We further corroborate the existence of superconductivity at zero chemical potential, through a fluctuation analysis on our solution. Notably, the conductivity of the system, as a function of probing frequency, exhibits characteristics of usual holographic superconductors. We also investigate how these properties of the system changes, as we vary the interaction strength between the scalar fields. Our results indicate a controlled mechanism to manipulate the phase transition temperature of superconductors with strongly coupled microscopics.
Particle fractionalization is believed to orchestrate the physics of many strongly correlated systems, yet its direct experimental detection remains a challenge. We propose a simple measurement for an ultracold matter system, in which correlations in initially decoupled 1D chains are imprinted via quantum quench upon two-dimensional Dirac fermions. Luttinger liquid correlations launch relativistic "fractionalization waves" along the chains, while coupling noninteracting chains induces perpendicular dispersion. These could be easily distinguished in an ultracold gas experiment.
Nature Materials. doi:10.1038/nmat4374
Authors: Chuan Xu, Libin Wang, Zhibo Liu, Long Chen, Jingkun Guo, Ning Kang, Xiu-Liang Ma, Hui-Ming Cheng & Wencai Ren