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An experimental demonstration of a non-classical state of a nanomechanical resonator is still an outstanding task. In this paper we show how the resonator can be cooled and driven into a squeezed state by a bichromatic microwave coupling to…

Mesoscale and Nanoscale Physics · Physics 2009-12-20 P. Rabl , A. Shnirman , P. Zoller

Entanglement is the central resource of quantum information processing and the precise characterization of entangled states is a crucial issue for the development of quantum technologies. This leads to the necessity of a precise,…

In this letter, we report on the time- and space-resolved measurement of subradiant excited state population in an ultra-cold atomic cloud of 174Yb atoms. We use a depletion imaging technique that exploits the V-type internal energy…

Accurate temperature estimation in the quantum and cryogenic regimes remains a fundamental challenge. Here, we investigate nonequilibrium quantum thermometry using a single-qubit probe coupled to a bosonic bath through noncommuting…

Quantum Physics · Physics 2025-12-23 Youssef Aiache , Abderrahim El Allati , İlkay Demir , Khadija El Anouz

Many experiments in quantum information aim at creating multi-partite entangled states. Quantifying the amount of entanglement that was actually generated can, in principle, be accomplished using full-state tomography. This method requires…

Quantum Physics · Physics 2015-05-13 Harald Wunderlich , Martin B. Plenio

We study temperature estimation using quantum probes, including single-mode initial states and two-mode states generated via stimulated parametric down-conversion in a nonlinear crystal at finite temperature. We explore both transient and…

Quantum Physics · Physics 2025-12-16 Asghar Ullah , M. Tahir Naseem , Özgür E. Müstecaplıoğlu

Quantum computers have the potential to solve certain interesting problems significantly faster than classical computers. To exploit the power of a quantum computation it is necessary to perform inter-qubit operations and generate entangled…

Mesoscale and Nanoscale Physics · Physics 2013-04-09 Michael D. Shulman , Oliver E. Dial , Shannon P. Harvey , Hendrik Bluhm , Vladimir Umansky , Amir Yacoby

We simulate the excited states of the Lipkin model using the recently proposed Quantum Equation of Motion (qEOM) method. The qEOM generalizes the EOM on classical computers and gives access to collective excitations based on quasi-boson…

Quantum integrable models display a rich variety of non-thermal excited states with unusual properties. The most common way to probe them is by performing a quantum quench, i.e., by letting a many-body initial state unitarily evolve with an…

We investigate coupled-qubit-based thermal machines powered by quantum measurements and feedback. We consider two different versions of the machine: 1) a quantum Maxwell's demon where the coupled-qubit system is connected to a detachable…

Quantum Physics · Physics 2023-05-03 Bibek Bhandari , Robert Czupryniak , Paolo Andrea Erdman , Andrew N. Jordan

Low-capacitance Josephson junction systems as well as coupled quantum dots, in a parameter range where single charges can be controlled, provide physical realizations of quantum bits, discussed in connection with quantum computing. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alexander Shnirman , Gerd Schoen

We propose a novel approach to define and measure the statistics of work, internal energy and dissipated heat in a driven quantum system. In our framework the presence of a physical detector arises naturally and work and its statistics can…

Quantum Physics · Physics 2015-10-28 P. Solinas , S. Gasparinetti

Employing spins in quantum dots for fault-tolerant quantum computing in large-scale qubit arrays with on-chip control electronics requires high-fidelity qubit operation at elevated temperature. This poses a challenge for single spin…

Mesoscale and Nanoscale Physics · Physics 2024-04-01 R. Jansen , S. Yuasa

Inspired by the idea that quantum computers can be useful in advancing basic science, we use a quantum processor to experimentally validate a number of theoretical results in non-equilibrium quantum thermodynamics, that were not (or were…

Quantum Physics · Physics 2021-10-01 Andrea Solfanelli , Alessandro Santini , Michele Campisi

We revisit quantum phase estimation algorithms for the purpose of obtaining the energy levels of many-body Hamiltonians and pay particular attention to the statistical analysis of their outputs. We introduce the mean phase direction of the…

Quantum Physics · Physics 2020-08-20 P. M. Q. Cruz , G. Catarina , R. Gautier , J. Fernández-Rossier

We consider two separated oscillators initially in equilibrium and continuously interacting with thermal environments, and propose a way to entangle them using a mediating qubit. An appropriate interaction allows for an analytic treatment…

Quantum Physics · Physics 2009-12-11 Tommaso Tufarelli , M. S. Kim , Sougato Bose

The controlled preparation of the excited state in a quantum emitter is a prerequisite for its usage as single-photon sources - a key building block for quantum technologies. In this paper we propose a coherent excitation scheme using…

Fault-tolerant quantum computing requires initializing the quantum register in a well-defined fiducial state. In solid-state systems, this is typically achieved through thermalization to a cold reservoir, such that the initialization…

The phenomenon of Coherent Population Trapping (CPT) of an atom (or solid state "artificial atom"), and the associated effect of Electromagnetically Induced Transparency (EIT), are clear demonstrations of quantum interference due to…

We introduce a measure Q of bipartite quantum correlations for arbitrary two-qubit states, expressed as a state-independent function of the density matrix elements. The amount of quantum correlations can be quantified experimentally by…

Quantum Physics · Physics 2012-04-16 Davide Girolami , Gerardo Adesso