Seminars 2023
This series of informative seminars on quantum technologies has the goal of providing an introduction on the hottest topics in the field. The targeted audience includes students and non expert researchers.
Those who are interested to attend to the seminars are invited to subscribe the mailing list to receive the links to the video conference. Contacts: Angelo Nucciotti, Andrea Giachero
How "quantum" is this?
Statistical tests of quantumness, from foundations to technologies
Statistical tests of quantumness, from foundations to technologies
Francesco Buscemi
(Nagoya University, Japan)
(Nagoya University, Japan)
March 16th 2023, 17.00 CEST
Physics Department U2, Room U2-02 (+ zoom)
Università di Milano-Bicocca
Piazza della Scienza 3, 20126 Milano
Physics Department U2, Room U2-02 (+ zoom)
Università di Milano-Bicocca
Piazza della Scienza 3, 20126 Milano
Abstract and material
With the increasing expectations for quantum technologies, a fundamental question common to a variety of areas of quantum information science is how to define the boundary between classical (that is, classically simulatable) and quantum (that is, truly beyond classical theory) devices, and how to provide criteria for certifying and benchmarking the "degree of quantumness" of any given device. Certainly, such a question is inherently multifaceted and allows for many (often non-equivalent) approaches. In this talk, I will focus on statistical tests of various embodiments of quantumness, ranging from bipartite resources to quantum memories and measurements, but keeping in mind a unified conceptual framework that I identify in the theory of "statistical comparisons" from mathematical statistics.
slides - video recording
Building the commons of quantum technology
Nathan Shammah
(Unitary Fund, Berkeley, USA)
(Unitary Fund, Berkeley, USA)
May 29th 2023, 17.00 CEST
Physics Department U2, Room U2-01 (+ zoom)
Università di Milano-Bicocca
Piazza della Scienza 3, 20126 Milano
Physics Department U2, Room U2-01 (+ zoom)
Università di Milano-Bicocca
Piazza della Scienza 3, 20126 Milano
Abstract and material
In this talk, I will give an overview of Unitary Fund's community and research activities in quantum technology. Unitary Fund (https://unitary.fund/) is a non-profit research organization that supports open-source software in quantum computing. It organizes hackathons, online discussions and awards grants to explorers in the field of quantum technology. It supports established projects like QuTiP, the quantum toolbox in Python [1]. Its technical team is developing two main projects: Mitiq, an open-source Python compiler for quantum error mitigation on noisy quantum processors [2-3], and Metriq, a crowd-sourced platform that enables benchmarking quantum computers (https://metriq.info/).
[1] B. Li et al., "Pulse-level noisy quantum circuits with QuTiP", Quantum 6, 630 (2022);
[2] R. LaRose et al., "Mitiq: A software package for error mitigation on noisy quantum computers", Quantum 6, 774 (2022):
[3] V. Russo et al., "Testing platform-independent quantum error mitigation on noisy quantum computers", 2210.07194v2 [quant-ph] .
Electrical properties of Ge spin-3/2 hole qubits
Dimi Culcer
(The University of New South Wales, Sydney (Australia))
(The University of New South Wales, Sydney (Australia))
October 3rd 2023, 14.30 CEST
Dipartimento di Scienze dei Materiali, U5
Seminar Room 1st floor
Università di Milano-Bicocca
Piazza della Scienza 3, 20126 Milano
Dipartimento di Scienze dei Materiali, U5
Seminar Room 1st floor
Università di Milano-Bicocca
Piazza della Scienza 3, 20126 Milano
Abstract and material
Strong spin-orbit interactions make hole quantum dots central to the quest for electrical spin qubit manipulation enabling fast, low-power, scalable quantum computation. Yet it is important to establish to what extent spin-orbit coupling exposes qubits to electrical noise, facilitating decoherence. Here, taking first Ge as an example, I will show that group IV gate-defined hole spin qubits generically exhibit sweet spots, defined by the top gate electric field, at which they are fast and long-lived: the dephasing rate vanishes to first order in electric field noise along all directions in space, the electron dipole spin resonance strength is maximised, while relaxation is drastically reduced at small magnetic fields. The existence of sweet spots is traced to group IV crystal symmetry and properties of the Rashba spin-orbit interaction unique to spin-3/2 systems. I will show that similar findings apply to Si. Our results overturn the conventional wisdom that fast operation implies reduced lifetimes, and suggest group IV hole spin qubits as ideal platforms for ultrafast, highly coherent scalable quantum computing [1].
1. Zhanning Wang, Elizabeth Marcellina, Alex Hamilton, James Cullen, Sven Rogge, Joe Salfi, and Dimi Culcer, NPJ Quantum Information 7, 54 (2021).
slides