Quantum resources have entered the many body state over the last two decades. Apart from the prototypical case of entanglement, relatively little is known about how such resources relate to physical phenomena, a question that is of pivotal importance for the understanding of quantum simulators and computers as many-body systems.
In this talk, I will show how magic - a type of resource that...
Dimensionality plays an essential role in determining the nature and properties of quantum gases. Fruitful physics may appear at the crossover between dimensions. In the current generation of cold atom experiments, the dimensionality of the system can be controlled by optical lattices. In this talk, I will firstly present our recent study of strongly-interacting bosons at 2D-1D dimensional...
Superconducting junction arrays constitute a versatile and tunable platform to engineer model Hamiltonians that are relevant for quantum many-body systems, dissipative quantummechanics, and non-linear quantum optics. We investigate the detailed AC spectroscopy of the boundary sine-Gordon (BSG) model for a circuit designed with a large impedance value below the resistance quantum. This regime...
This talk will present our recent work on the use of arrays of Rydberg atoms to study equilibrium and out-of-equilibrium quantum magnetism and to generate entangled states useful for quantum metrology. We rely on laser-cooled ensembles of up to one hundred individual atoms trapped in microscopic optical tweezer arrays. By exciting the atoms into Rydberg states, we make them interact by the...
We study the thermodynamics of free-fermion systems coupled to quantum
thermal baths within a Markovian approximation. In particular, we construct
a four-stroke quantum Otto engine by alternately coupling such kind of
systems to two reservoirs at different temperatures and operating adiabatic
switches of some Hamiltonian parameters, followed by isochoric transformations.
We show that...
The localization-delocalization transition in disordered media is ubiquitous in quantum and classiacal systems. It is one of the rare transition for which there is no mean-field theory valid in any dimensions. We report the observation and characterization of the Anderson transition in 4D using ultracold atoms as a quantum simulator with synthetic dimensions.
We characterize the universal...
Quasicrystals, a fascinating class of materials with long-range but nonperiodic order, exhibit fascinating properties due to their unique position at the crossroads of long-range-ordered and disordered systems. These include remarkable localization and fractal properties. While such properties are well known for single particles, the strongly-correlated regime remains largely unexplored....
The elementary excitations in weakly interacting quantum fluids have a non-trivial nature which is at the basis of defining quantum phenomena such as superfluidity. These excitations and the physics they lead to have been explored in closed quantum systems at thermal equilibrium both theoretically within the celebrated Bogoliubov framework, and experimentally in quantum fluids of ultracold...
Quantum gas microscopy (QGM) provides unique access to the properties of quantum many-body system in- and out-of-equilibrium. In this talk, I will report recent work on thermalizationdynamics of hard-core bosons in quasi-1D systems. We make use of site-resolved densitysnapshots in order to monitor the full counting statistics of particle-number fluctuations inoptical ladders, contrasting...
Quantum simulators realize the most controlled forms of quantum matter, in which one can hope to both design and probe many-body quantum coherence and entanglement. Pursuing this program away from equilibrium offers a much richer palette of entangled states than those possible in equilibrium systems; and the possibility to reach these states in a short time, a fundamental advantage for...
The ETH addresses the structure of matrix elements of local operators in energy eigenstates of generic systems. I will discuss what replaces the ETH for integrable systems.
I will present joint work with Léa Dubois, Guillaume Thémèze Florence Nogrette and Isabelle Bouchoule (Institut d’Optique, Palaiseau, France) on the measurement of the local rapidity distribution in 1D Bose gases.
1D bosons with point-like interaction, also known as Lieb-Liniger gas, display peculiar dynamical behavior because they are (nearly) integrable. The rapidities of a 1D Bose gas are...
Complex quantum systems are both hard to simulate and to learn. Generically, they require exponential resources for both. If one were able to learn and then efficiently simulate a complex quantum process, then one would be able to do wonders: for example, to decode the information scrambled by a black hole leaked through Hawking radiation, thus learning its internal structure.
Some complex...
I shall discuss the two newly discovered molecular BEC: those of ground state dipolar molecules of NaCs achieved in January 2024, and those of G-wave Feshbach molecules realized in 2023. I shall discuss their phase coherence different from those of the atomic BECs.
Quench and lattice modulation are powerful tools for probing low-energy excitations of interacting many-body systems. We present a study of correlation dynamics and absorbed energy power of one-dimensional interacting systems (fermionic and bosonic) subjected either to a quench or to a periodic drive of the optical lattice. For these Tomonaga-Luttinger liquids we find a universal scaling of...
Monitored quantum systems undergo Measurement-induced Phase Transitions (MiPTs) stemming from the interplay between measurements and unitary dynamics. When the detector readout is post-selected to match a given value, the dynamics is generated by a Non-Hermitian Hamiltonian with MiPTs characterized by different universal features.
Here, we present a partial post-selected stochastic...
In this presentation, we consider situations where the existence of a contiguous cascade of quantum resonant transitions is predicated on the validity of a particular statement in number theory. As a case study, we look at the following trivial statement: "Any power of 3 is an integer."
Consequently, we "test" this statement in a numerical experiment where we demonstrate an un-impeded...
I plan to start the seminar by presenting a discussion of the experimental realization with holographic techniques of the prime number quantum potential, defined as the potential entering the single-particle Schrödinger Hamiltonian with eigenvalues given by the first N prime numbers. We also implemented the potential having as eigenvalues the first lucky numbers, a sequence of integers...
My talk focuses on strongly repulsive one-dimensional gases consisting of two-equally balanced spin components under a box confinement. We describe these systems using a generalized Tonks-Girardeau ansatz for the many-body wave function [1, 2].
In particular, we are interested in the nonequilibrium dynamics induced by the initial separation of the spin components and the subsequent...
Alkaline-earth and ytterbium cold atomic gases make it possible to simulate SU(N)-symmetric fermionic systems in a very controlled fashion. Such a high symmetry is expected to give rise to a variety of novel phenomena ranging from molecular Luttinger liquids to (symmetry-protected) topological phases.
I will discuss some of the phases that can be stabilized in a one dimensional lattice,...
We consider a quantum lattice spin model featuring exact quasiparticle towers of eigenstates with low entanglement at finite size, known as quantum many-body scars (QMBS). We show that the states in the neighboring part of the energy spectrum can be superposed to construct entire families of low-entanglement states whose energy variance decreases asymptotically to zero as the lattice size is...
In this talk I will describe our research on QAOA-like algorithms, in which a quantum simulator is used for brief periods of time, in combination with local drives. We have shown in Ref. [1] that using a quantum simulator for an Ising mode just once, for an arbitrarily brief period of time, results in a pure state that resembles a Boltzmann distribution up to a limiting temperature, that...
L. Maffi, N. Tausendpfund, M. Rizzi, M. Burrello
Modern hybrid superconductor-semiconductor Josephson junction arrays are a promising platform for analog quantum simulations. Their controllable and non-sinusoidal energy/phase relation opens the path to implement nontrivial interactions and study the emergence of exotic quantum phase transitions. Here, we propose the analysis of an array of...
The Hall effect originates from the motion of charged particles in a magnetic field and
has deep consequences for the description and characterization of materials, far beyond
the context of condensed matter physics. Understanding the Hall effect in interacting
systems still represents a fundamental challenge.
Identifying experimentally accessible probes that are able to reveal truly distinctive properties of topological phases of matter has remained as an ever-relevant mission. In this talk, I will start reviewing recent advances that were made possible thanks to a remarkable thermodynamic relation known as the Widom-Středa formula, which relates the quantized Hall conductivity of an insulator to...
