Reversible to Irreversible Flow Transition in Periodically Driven Vortices

Abstract

We show that periodically driven superconducting vortices in the presence of quenched disorder exhibit a transition from reversible to irreversible flow under increasing vortex density or cycle period. This type of behavior has recently been observed for periodically sheared colloidal suspensions and we demonstrate that driven vortex systems exhibit remarkably similar behavior. We also provide evidence that the onset of irreversible behavior is a dynamical phase transition.PACS numbers: 82.70.Dd Recent experiments on periodic shearing of colloidal suspensions in a viscous media where thermal effects are negligible have shown a transition from reversible behavior to an irreversible motion as a function of increasing particle density [1,2]. The reversible and irreversible regimes were identified by measuring the net displacement of the colloids after each cycle of a periodic shear. In the reversible regime, the colloids return to their initial position at the end of each cycle, while in the irreversible regime, the colloids do not return to their starting point. A stroboscopic measurement of the displacements in the irreversible regime reveals that the colloids undergo an anisotropic random walk, with larger displacements in the shear direction. For a given colloid density, there is a threshold for the transition from reversible to irreversible behavior as a function of the strain amplitude or the distance the particles are sheared per cycle. The strain threshold decreases as the colloid concentration increases, indicating that colloid-colloid interactions play an important role in the transition. More recent modeling of this system has provided evidence that the reversible to irreversible transition is a nonequilibrium phase transition with power law divergences near the transition [3]. Other experiments on dilute sheared colloidal suspensions also indicate the importance of the particle interactions in producing irreversible or chaotic flow behaviors [4].In this work, we consider whether the general features of the reversible and irreversible behaviors observed in the sheared colloidal system can be realized in a wider class of nonequilibrium many-particle systems. Driven particles moving over random quenched disorder provide an ideal class of systems for studying this issue [5]. Physical realizations of such systems include vortices in type-II superconductors [6,7], driven Wigner crystals [8], magnetic bubble arrays [9], driven pattern forming systems [10], and colloids moving over random landscapes [11]. In the presence of strong quenched disorder, plastic flow regimes occur in these systems even in the absence of any thermal effects. In the case of vortices, it has been established that transitions from plastic flow to smectic or elastic flow states can be induced as a function of increasing dc driving force [6]. It is not known whether there could also be a reversible to irreversible flow transition in the presence of some form of periodic forcing.To address this question, we examine the specific system o...

Precisely cyclic sand: Self-organization of periodically sheared frictional grains

“…Here, there is a clear route to reversibility, because at low Reynolds numbers the equations of motion for the fluid are reversible, and irreversibility is only introduced through particle collisions or potential interactions. A similar cyclic behavior has been observed in periodically driven superconducting vortices (4), which interact via a nonlinear potential.…”

“…granular | self-organization | limit cycles | friction S elf-organization under periodic driving is a common feature in many disparate far-from-equilibrium systems (1)(2)(3)(4). Recently, there has been substantial interest in self-organization in suspensions under slow, cyclic, low-Reynolds number shear (1,5,6).…”

Closer look at the low-frequency dynamics of vortex matter using scanning susceptibility microscopy

“…As stated in Ref. [8], random pinning potentials smoothed over the scale of ∼ξ represent a more realistic scenario for weak-pinning materials like NbSe 2 as compared, for instance, to models of diluted, nonoverlapping distributions of parabolic traps [13,16,32,33].…”

“…Although particular effort has been devoted to understand the dynamic behavior under dc drive, somewhat less attention has been paid to ac excitations [10][11][12][13][14][15][16]. Unfortunately, the extrapolation of the findings obtained under dc drive to predict the ac dynamics is not always straightforward.…”

Random organization of vortices under an anisotropic condition

“…Introduction A many particle system under an external driving force exhibits rich intriguing phenomena and has attracted much attention in recent years [1][2][3][4][5][6][7]. When particles are subjected to a periodic shear force, they collide with each other and gradually self-organize to avoid future collisions.…”