April 2021 - Materia-seminarios

Recordatorio de Webminar: Mpemba effect in Markovian open quantum systems
by Daniel Manzano 22 Apr '21

22 Apr '21

El Grupo de Física Estadística de los Sistemas Complejos de la Universidad de Granada les invita al siguiente seminario online: Speaker: Dr. Federico Carollo. University of Tübingen. Title: Mpemba effect in Markovian open quantum systems Abstract: The Mpemba effect is the phenomenon for which a hotter liquid can cool at a faster rate than a colder one. This effect is nowadays receiving much attention; it has been predicted for different classical systems and it has even been observed experimentally for a trapped colloid particle. In this talk, I will propose an analogue of the Mpemba effect for Markovian open quantum systems. I will show that the relaxation dynamics of these systems can be exponentially accelerated by devising an optimal unitary transformation, that is applied to the quantum state immediately before the actual dynamics. This preliminary “rotation” is engineered in such a way that the state of the quantum system becomes orthogonal to the slowest decaying dynamical mode. I will illustrate potential applications of this effect by showing how it can be used to achieve an exponential speed-up in the convergence to stationarity in Dicke models as well as to avoid metastable regimes in an all-to-all interacting spin system. Date and time: Friday, April 23rd, 12:00. Link: https://meet.google.com/smu-dsfx-mqk <https://meet.google.com/smu-dsfx-mqk> --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/>

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Webminar: Mpemba effect in Markovian open quantum systems
by Daniel Manzano 20 Apr '21

20 Apr '21

El Grupo de Física Estadística de los Sistemas Complejos de la Universidad de Granada les invita al siguiente seminario online: Speaker: Dr. Federico Carollo. University of Tübingen. Title: Mpemba effect in Markovian open quantum systems Abstract: The Mpemba effect is the phenomenon for which a hotter liquid can cool at a faster rate than a colder one. This effect is nowadays receiving much attention; it has been predicted for different classical systems and it has even been observed experimentally for a trapped colloid particle. In this talk, I will propose an analogue of the Mpemba effect for Markovian open quantum systems. I will show that the relaxation dynamics of these systems can be exponentially accelerated by devising an optimal unitary transformation, that is applied to the quantum state immediately before the actual dynamics. This preliminary “rotation” is engineered in such a way that the state of the quantum system becomes orthogonal to the slowest decaying dynamical mode. I will illustrate potential applications of this effect by showing how it can be used to achieve an exponential speed-up in the convergence to stationarity in Dicke models as well as to avoid metastable regimes in an all-to-all interacting spin system. Date and time: Friday, April 23rd, 12:00. Link: https://meet.google.com/smu-dsfx-mqk --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/>

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[Recordatorio] Webminar: From quantum simulations of fermionic models to continuous-variable quantum computation.
by Daniel Manzano 15 Apr '21

15 Apr '21

El grupo de Física Estadística de los Sistemas Complejos de la Universidad de Granada les invita al siguiente seminario (atentos a la hora no habitual): Fecha y hora: Viernes 16 de Abril. 10:30. Ponente: Laura García-Álvarez. Chalmers University of Technology. Title: From quantum simulations of fermionic models to continuous-variable quantum computation. Abstract: Firstly, I will introduce digital-analog and purely digital methods for quantum simulations of fermionic models. The digital-analog approach provides a higher degree of scalability than purely digital or analog techniques, and it is suitable for implementing quantum simulations of interacting fermions and bosons in condensed matter, and quantum field theories [1]. Purely digital quantum simulations [2,3,4] are grouped under standard discrete-variable quantum computation, while analog quantum simulators with bosonic fields can be described with the language of continuous-variable (CV) quantum computation. The second part of the talk is devoted to analyzing the factors that may yield quantum advantage. In particular, Wigner negativity is known to be a necessary resource for computational advantage in several quantum-computing architectures, including those based on continuous variables [5,6]. However, it is not a sufficient resource, and it is an open question under which conditions CV circuits displaying Wigner negativity offer the potential for quantum advantage. I will present large families of circuits that display large Wigner negativity and yet are classically efficiently simulatable [7], although they were not recognized as such by previously available theorems. References: [1] L. García-Álvarez et al., Fermion-fermion scattering in quantum field theory with superconducting circuits, Phys. Rev. Lett. 114, 070502 (2015). [2] R. Barends et al., Digital quantum simulation of fermionic models with a superconducting circuit, Nat. Commun. 6, 7654 (2015). [3] J. M. Kreula et al., Few-qubit quantum-classical simulation of strongly correlated lattice fermions, EPJ Quantum Technology 3, 11 (2016). [4] L. García-Álvarez et al., Digital quantum simulation of minimal AdS/CFT, Phys. Rev. Lett. 119, 040501 (2017). [5] A. Mari and J. Eisert, Phys. Rev. Lett. 109, 230503 (2012). [6] V. Veitch, N. Wiebe, C. Ferrie, and J. Emerson, New J. of Phys. 15, 013037 (2013). [7] L. García-Álvarez et al., Efficient simulatability of continuous-variable circuits with large Wigner negativity, Phys. Rev. Research 2, 043322 (2020). Enlace: https://meet.google.com/wmk-nsik-qyz <https://meet.google.com/wmk-nsik-qyz> --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/> --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/>

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Webminario: From quantum simulations of fermionic models to continuous-variable quantum computation.
by Daniel Manzano 13 Apr '21

13 Apr '21

El grupo de Física Estadística de los Sistemas Complejos les invita al siguiente seminario (atentos a la hora no habitual): Fecha y hora: Viernes 16 de Abril. 10:30. Ponente: Laura García-Álvarez. Chalmers University of Technology. Title: From quantum simulations of fermionic models to continuous-variable quantum computation. Abstract: Firstly, I will introduce digital-analog and purely digital methods for quantum simulations of fermionic models. The digital-analog approach provides a higher degree of scalability than purely digital or analog techniques, and it is suitable for implementing quantum simulations of interacting fermions and bosons in condensed matter, and quantum field theories [1]. Purely digital quantum simulations [2,3,4] are grouped under standard discrete-variable quantum computation, while analog quantum simulators with bosonic fields can be described with the language of continuous-variable (CV) quantum computation. The second part of the talk is devoted to analyzing the factors that may yield quantum advantage. In particular, Wigner negativity is known to be a necessary resource for computational advantage in several quantum-computing architectures, including those based on continuous variables [5,6]. However, it is not a sufficient resource, and it is an open question under which conditions CV circuits displaying Wigner negativity offer the potential for quantum advantage. I will present large families of circuits that display large Wigner negativity and yet are classically efficiently simulatable [7], although they were not recognized as such by previously available theorems. References: [1] L. García-Álvarez et al., Fermion-fermion scattering in quantum field theory with superconducting circuits, Phys. Rev. Lett. 114, 070502 (2015). [2] R. Barends et al., Digital quantum simulation of fermionic models with a superconducting circuit, Nat. Commun. 6, 7654 (2015). [3] J. M. Kreula et al., Few-qubit quantum-classical simulation of strongly correlated lattice fermions, EPJ Quantum Technology 3, 11 (2016). [4] L. García-Álvarez et al., Digital quantum simulation of minimal AdS/CFT, Phys. Rev. Lett. 119, 040501 (2017). [5] A. Mari and J. Eisert, Phys. Rev. Lett. 109, 230503 (2012). [6] V. Veitch, N. Wiebe, C. Ferrie, and J. Emerson, New J. of Phys. 15, 013037 (2013). [7] L. García-Álvarez et al., Efficient simulatability of continuous-variable circuits with large Wigner negativity, Phys. Rev. Research 2, 043322 (2020). Enlace: https://meet.google.com/wmk-nsik-qyz <https://meet.google.com/wmk-nsik-qyz> --------------------------------------------------------------------------------- Daniel Manzano Electromagnetism and Condensed Matter Department Institute “Carlos I” for Theoretical and Computational Physics University of Granada Facultad de Ciencias, Av. Fuentenueva s/n Granada 18071, Spain Phone: +34 958241000 Ext: 20569 http://ic1.ugr.es/manzano/ <http://ic1.ugr.es/manzano/>

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