Group seminars

Only some of the recent local seminars are shown.


Iagoba Appellaniz (UPV/EHU), Journal club: M. Fadel, B. Yadin, Y. Mao, T. Byrnes, M. Gessner, Multiparameter quantum metrology and mode entanglement with spatially split nonclassical spin states, arXiv.2201.11081, 14:30, 11 November, 2022.


Title:  Permutation invariant multipartite entanglement and correlations [pdf]

Speaker:  Szilárd Szalay

Abstract: We briefly review the partial separability based classification of mixed states of multipartite quantum systems of arbitrary number of subsystems, and show how this structure simplifies in the case when not entanglement but correlation is considered. As special cases, we consider the notions of k-separability and k-producibility (as well as their correlational versions), reveal how these are dual to each other. This duality can be seen from a much wider perspective, when we consider the entanglement and correlational properties which are invariant under the permutations of the subsystems. This general treatment reveals a new property, which we call k-stretchability of entanglement, being sensitive in a balanced way to both the maximal size of correlated (or entangled) subsystems and the minimal number of subsystems uncorrelated (or separable) from one another. We also give the corresponding multipartite correlation and entanglement monotones, being the natural generalizations of mutual information, entanglement entropy and entanglement of formation or relative entropy of entanglement, showing the same lattice structure as the classification (multipartite monotonicity). As illustration, we show some examples coming from molecular-physics.

Date:  Thursday, 11 November 2021

Tine: 11:40 am

Location: Seminar Room, Department of Theoretical Physics


Title:  Stability analysis of electroweak-dark strings [pdf]

Speaker:  Árpad Lukács

Abstract:  The stability of  "visible" electroweak-type cosmic strings is investigated in an extension of the Standard Model (SM) by a minimal dark sector, consisting of a U(1) gauge field, broken spontaneously by a scalar. The "visible" and dark sectors are coupled through a Higgs-portal and a gauge-kinetic mixing term. It is found that strings whose core is "filled" with a dark scalar condensate exhibit better stability properties than their analogues in the SM, when the electroweak mixing angle is close to theta=pi/2. They become  unstable as one lets theta approach its physical value. The instability mechanism appears to be a W-boson condensation mechanism found in previous studies on the stability of electroweak strings.

Date:  Wednesday, 11 March 2020

Tine: 11:40 am

Location: Seminar Room, Department of Theoretical Physics


N. Muñoz (UPV/EHU), Quantum mechanics with real numbers, A6.P1.5., 15:00–16:00, 6 June 2017.


Student journal club (within the Graduate course in the Master's program in Quantum Science and Technology at UPV/EHU)

Place: ZTF 0.13
Time: 16:00, Thursday, 23 March, 2017

Ibai Aedo Goñi

Mikel Alvarez Urquiola

Emma Campillo Muñoz

Daniel Martinez Cercos

Nuria Muñoz Gargante

Miguel Peidro Montava

Ibai Zabala Cordobes


M. Kleinmann (UPV), Emergence of Quantum Bipartite Correlations & Dvorezky's theorem, A6.P1.5., 12:00–13:00, 22 March 2017.


F. Huber (University of Siegen, Germany), Absolutely Maximal Entangled States, Faculty of Sciences, A6.P1.5., 12:00-13:00, 9 December 2016.


D. Sokolovski (UPV/EHU), Weak measurements, Seminar room of the Department of Physical Chemistry, 11:30-13:00, 2 November 2016.


M. Kleinmann (UPV/EHU), A primer on contextuality, Seminar room of the Department of Theoretical Physics, 15:00-16:00, 25 October 2016.


Gael Sentis (UPV/EHU), Decomposition of POVMs to extremal POVMs, 11:00, 28 of April, 2016.


Giuseppe Vitagliano (UPV/EHU), Gabriel Fagundes (UPV/EHU) and Iagoba Apellaniz (UPV/EHU), Group Seminars: Trial talks for DPG Spring Meeting and Recent Advances in QM , 11:00, 25 of February, 2016.


Giuseppe Vitagliano (UPV/EHU), Journal club: E. Shchukin and P. van Loock, Phys. Rev. A 92, 042328 (2015), 11:00, 3 of February, 2016.


Matthias Kleinmann (UPV/EHU), Journal club: "Why a qubit is not a quantum coin". 11:00, 28 of January, 2016.


Giuseppe Vitagliano (UPV/EHU), Journal club: R. Augusiak, J. Kolodynski, A. Streltsov, M. Nath Bera, A. Acin, M. Lewenstein, Asymptotic irrelevance of entanglement in quantum metrology, arxiv:1506.08837, 11:00, 17 December, 2015.


Iagoba Apellaniz  (UPV/EHU), Journal club: F. Fröwis, P. Sekatski, and W. Dür, Detecting large quantum Fisher information with finite measurement precision, arxiv:1509.03334, 11:00, 3 December, 2015.


Giuseppe Vitagliano  (UPV/EHU), Seminar on spin squeezing inequalities detecting Dicke states, 15:00, 2 December, 2015.


Trial of Ph.D. talk of Giuseppe Vitagliano, Sala 4, Faculty of Sciences, 15:00, 7 October, 2015.


Seminar of Gael Sentis (UPV/EHU), 17 June, 2015.


Trial presentations preparing for the Conference of the Germany Physical Society in Heidelberg, Seminar room of the Department of Theoretical Physics, 12:00-13:00, 18 March 2015.


Trial presentations preparing for the Conference of the Germany Physical Society in Heidelberg, Sala 4, 15:00-16:00, 17 March 2015.


G. Vitagliano, Journal club: Q. Y. He, Shi-Guo Peng, P. D. Drummond, and M. D. Reid, Planar quantum squeezing and atom interferometry, Phys. Rev. A 84, 022107 (2011), G. Puentes, G. Colangelo, R.J. Sewell, and M.W. Mitchell, Planar squeezing by quantum non-demolition measurement in cold atomic ensembles, New J. Phys. 15, 103031 (2013), 12:00-13:00, 3 March, 2015.


Student journal club (within the Graduate course in the Master's program in Quantum Science and Technology at UPV/EHU)

Place: Seminar Room, Dept. of Theoretical Physics, Corridor 4.-2.
Time: 11:00, Wednesday, 18 March,2015

Iñigo Arrazola: No-cloning theorem
Hodei Eneriz: Separability Criterion for Density Matrices (A. Peres)

Alfredo Serrano: Universal Optimal Cloning of Arbitrary Quantum States:  From Qubits to Quantum Registers (V. Buzek, M. Hillery)


S. Altenburg, Journal club: H. Strobel, W. Muessel, D. Linnemann, T. Zibold, D.B. Hume, L. Pezzè, A. Smerzi, and M.K. Oberthaler, Fisher information and entanglement of non-Gaussian spin state, 12:00-13:00, 12 February, 2015.


G. Vitagliano, The Leggett-Garg inequality - discussion of a draft (group seminar), Department of Theoretical Physics, University of the Basque Country UPV/EHU, 15:30, 2 December 2014.


G. Vitagliano, The Leggett-Garg inequality (group seminar), Department of Theoretical Physics, University of the Basque Country UPV/EHU, 15:30, 14 May 2014.


25 March: Student journal club (within the Graduate course in the Master's program in Quantum Science and Technology at UPV/EHU)

Place: Seminar Room, Dept. of Theoretical Physics, Corridor 4.-2.
Time: 11:00, Tuesday, 25 March, 2013

11:00-11:25: Xabi Lopez Gonzalez: Separability Criterion for Density Matrices (A. Peres)

11:25-11:50: Urtzi las Heras: Quantum Cryptography Based on Bell's Theorem (A.K. Ekert)

11:50-12:00: Break

12:00-12:25: Laura Garcia Alvarez: Universal Optimal Cloning of Arbitrary Quantum States: From Qubits to Quantum Registers (V. Buzek and M. Hillary)

12:25-12:50: Iker Leanizbarrutia Alonso: A single quantum cannot be cloned (W.K. Wootters and W.H. Zurek)