Non-heating Floquet systems
| dc.contributor.author | Högberg, Michael | |
| dc.contributor.department | Chalmers tekniska högskola / Institutionen för fysik | sv |
| dc.contributor.examiner | Gran, Ulf | |
| dc.contributor.supervisor | Johannesson, Henrik | |
| dc.date.accessioned | 2020-12-16T13:34:05Z | |
| dc.date.available | 2020-12-16T13:34:05Z | |
| dc.date.issued | 2020 | sv |
| dc.date.submitted | 2020 | |
| dc.description.abstract | In the last decade there has been immense progress in experimentally realizing periodically driven, so-called Floquet systems, that exhibit topological features. However, there is an expectation that most Floquet systems heat up with time, absorbing energy from the drive, and thus evolve towards a featureless state in which all local correlations are fully random. In this thesis it is shown that it is theoretically possible to have a Floquet system which do not heat up, giving that any existing local correlations could be infinitely long lived. In other words, this shows that interesting physical phenomenon, such as a non-trivial topological phase, could in principal be present in a Floquet system for infinitely long times. The Floquet model which exhibits this non-heating phase is that of a square-wave drive where the Hamiltonian of the system jumps between an arbitrarily chosen CFT and a sine-square deformation of the same CFT. This model was first proposed in 2018 by Wen and Wu in Ref. [1]. We present in this thesis a generalization of the Floquet system proposed by Wen and Wu – we still use the same square wave drive but now with what we call a sine-k-square deformation, hence a deformation of higher harmonics. With this generalization we also find the interesting property of a non-heating phase for certain values of the driving parameters. Furthermore, we find that the value of k in the sine-k-squared deformation that we propose has some rather important implications for which driving parameter values we can have in a non-heating phase: The region of the driving parameter values which gives the non-heating phase shrinks with growing k. | sv |
| dc.identifier.coursecode | TIFX05 | sv |
| dc.identifier.uri | https://hdl.handle.net/20.500.12380/302137 | |
| dc.language.iso | eng | sv |
| dc.setspec.uppsok | PhysicsChemistryMaths | |
| dc.subject | CFT | sv |
| dc.subject | Floquet theory | sv |
| dc.subject | Floquet heating problem | sv |
| dc.subject | sine-square deformation | sv |
| dc.subject | sine-k-square deformation | sv |
| dc.title | Non-heating Floquet systems | sv |
| dc.type.degree | Examensarbete för masterexamen | sv |
| dc.type.uppsok | H | |
| local.programme | Physics and astronomy (MPPAS), MSc |