Heat current rectification in segmented XXZ chains

Abstract

We study the rectification of heat current in an XXZ chain segmented in two parts. We model the effect of the environment with Lindblad heat baths. We show that, in our system, rectification is large for strong interactions in half of the chain and if one bath is at cold enough temperature. For the numerically accessible chain lengths, we observe that the rectification increases with the system size. We gain insight in the rectification mechanism by studying two-time correlations in the steady state. The presence of interactions also induces a strong nonlinear response to the temperature difference, resulting in superlinear and negative differential conductance regimes. arXiv:1809.01917v2 [cond-mat.stat-mech]FIG. 3: Interface tunneling. Rectification ratio versus anisotropy ∆ for different magnitudes of the tunneling at the interface between the interacting and the non-interacting halves of the chain (purple circles for J N/2 = 0.1, blue squares for J N/2 = 0.2, red triangles for J N/2 = 0.5 and green diamonds for J N/2 = 1.0). The smaller the interface tunneling J N/2 the stronger the rectification effect, however larger are the resonance effects due to finite size. Other parameters are N = 8, TC = 0.1 and TH = 10.

Dynamical tides in coalescing superfluid neutron star binaries with hyperon cores and their detectability with third-generation gravitational-wave detectors

“…Lastly, because the dominating gmodes are excited at frequencies higher than the most sensitive band of ground-based GW detectors (≈ 70 Hz), larger f a have larger ∆(δφ a ) and ∆( f a ) and thus worse detectability. This is different from the results in Balachandran & Flanagan (2007) who found that increasing f a would make the detection easier, as Balachandran & Flanagan (2007) considered modes that were excited at frequencies lower than the most sensitive band.…”

“…Similar to Balachandran & Flanagan (2007), who also studied the detectability of mode resonances (see also Flanagan & Racine 2007), we assume that the frequency-domain GW signal has the form…”

“…Here t c and φ c are constants of integration that set a reference time and phase. The duration of each resonance is, in general, much shorter than the orbital decay timescale due to radiation reaction (their ratio is 0.1 × [(M/1.2M )( f /500 Hz)] 5/6 ; see Lai 1994;Flanagan & Racine 2007;Balachandran & Flanagan 2007). We therefore model the resonance as an instantaneous process, which should be a good approximation since nearly all the g-modes we consider have f (GR) a < 500 Hz (the one exception is the n a = 1 hyperonic g-mode of the 1.6M HS model which has f (GR) a = 740 Hz).…”

Anomalous Heat Transport in Classical Many-Body Systems: Overview and Perspectives

“…Furthermore, the use of local Lindblad baths may result in apparent violations of the second law of thermodynamics [123]. Global Lindblad dissipators are free from such problems and can be used to simulate heat transport (see e.g., [124]), but are not practical in that they are limited to very small system sizes. Furthermore, for the description of quantum heat engines in the extreme case where the working medium may even consist of a single two-level quantum system, it is crucial to take into account medium-reservoir quantum correlations as well as non-Markovian effects, which are not included in the standard, weak-coupling Lindblad description of quantum open systems.…”

Transport and Energetic Properties of a Ring of Interacting Spins Coupled to Heat Baths

“…Understanding transport properties in quantum systems can lead to various interesting applications such as quantum rectifiers [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ], transistors [ 14 ], engines [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ], refrigerators [ 32 , 33 , 34 , 35 , 36 , 37 ], and batteries [ 38 , 39 , 40 ]. In thermoelectric systems, one main goal is to achieve an electric current due to a temperature bias.…”