61 citations · 389 across the 27 of their papers we have counts for
27 papers
Simulating cavity QED with spin-orbit coupled Bose-Einstein condensates revisited
Muhammad S. Hasan, Karol Gietka
Simulating cavity quantum electrodynamics in synthetic platforms offers a route to studying light--matter physics without real photons. We reassess the frequently invoked analogy b…
Mind the Gap: Anti-Critical Quantum Metrology
George Mihailescu, Karol Gietka
Critical quantum metrology exploits the dramatic growth of the quantum Fisher information near quantum phase transitions to enhance the precision of parameter estimation. This enha…
Frequency shifts heralding ground state squeezing and entanglement of two coupled harmonic oscillators
Safoura Mirkhalaf, Helmut Ritsch, Karol Gietka
It is often argued that two linearly coupled quantum harmonic oscillators, even when cooled to their ground state, display no inherently quantum features beyond quantized energy le…
Critical Quantum Sensing: a tutorial on parameter estimation near quantum phase transitions
George Mihailescu, Uesli Alushi, Roberto Di Candia +2
Quantum phenomena offer the possibility of measuring physical quantities with precision beyond classical limits. However, current progress is constrained by scalability, environmen…
Quantum Metrology in the Ultrastrong Coupling Regime of Light-Matter Interactions: Leveraging Virtual Excitations without Extracting Them
Christoph Hotter, Adam Miranowicz, Karol Gietka
Virtual excitations, inherent to ultrastrongly coupled light-matter systems, induce measurable modifications in system properties, offering a novel resource for quantum technologie…
Conditional Entanglement Amplification via Non-Hermitian Superradiant Dynamics
Christoph Hotter, Arkadiusz Kosior, Helmut Ritsch +1
Due to the inherently probabilistic nature of quantum mechanics, each experimental realization of a dynamical quantum system may yield a different measurement outcome, especially w…
Uncertain Quantum Critical Metrology: From Single to Multi Parameter Sensing
George Mihailescu, Steve Campbell, Karol Gietka
Critical quantum metrology relies on the extreme sensitivity of a system's eigenstates near the critical point of a quantum phase transition to Hamiltonian perturbations. This mean…
Nonequilibrium Nonlinear Effects and Dynamical Boson Condensation in a Driven-Dissipative Wannier-Stark Lattice
Arkadiusz Kosior, Karol Gietka, Farokh Mivehvar +1
Driven-dissipative light-matter systems can exhibit collective nonequilibrium phenomena due to loss and gain processes on the one hand and effective photon-photon interactions on t…
Vacuum Rabi splitting as a manifestation of virtual two-mode squeezing: Extracting the squeezing parameters from frequency shifts
Karol Gietka
Vacuum Rabi splitting relies on symmetrical splitting of the common resonance frequency of atoms and the cavity in which the atoms reside. In this work, we argue that vacuum Rabi s…
Temperature-Enhanced Critical Quantum Metrology
Laurin Ostermann, Karol Gietka
We show that the performance of critical quantum metrology protocols, counter-intuitively, can be enhanced by finite temperature. We consider a toy-model squeezing Hamiltonian, the…
Combining critical and quantum metrology
Christoph Hotter, Helmut Ritsch, Karol Gietka
Critical metrology relies on the precise preparation of a system in its ground state near a quantum phase transition point where quantum correlations get very strong. Typically thi…
Unique Steady-State Squeezing in a Driven Quantum Rabi Model
Karol Gietka, Christoph Hotter, Helmut Ritsch
Squeezing is essential to many quantum technologies and our understanding of quantum physics. Here we develop a theory of steady-state squeezing that can be generated in the closed…
Squeezing of the quantum electromagnetic vacuum
Karol Gietka
It is commonly agreed that the electromagnetic vacuum is not empty but filled with virtual photons. This leads to effects like Lamb shift and spontaneous emission. Here we argue th…
Squeezing and overcoming the Heisenberg scaling with spin-orbit coupled quantum gases
Karol Gietka, Helmut Ritsch
We predict that exploiting spin-orbit coupling in a harmonically trapped spinor quantum gas can lead to scaling of the optimal measurement precision beyond the Heisenberg scaling.…
Distributed quantum sensing with optical lattices
Jose Carlos Pelayo, Karol Gietka, Thomas Busch
In distributed quantum sensing the correlations between multiple modes, typically of a photonic system, are utilized to enhance the measurement precision of an unknown parameter. I…
Harnessing the center-of-mass excitations in quantum metrology
Karol Gietka
In quantum metrology, one typically creates correlations among atoms or photons to enhance measurement precision. Here, we show how one can use other excitations to perform quantum…
Squeezing by Critical Speeding-up: Applications in Quantum Metrology
Karol Gietka
We present an alternative protocol allowing for the preparation of critical states that instead of suffering from the critical slowing-down benefits from the critical speeding-up.…
Inverted harmonic oscillator dynamics of the nonequilibrium phase transition in the Dicke model
Karol Gietka, Thomas Busch
We show how the dynamics of the Dicke model after a quench from the ground-state configuration of the normal phase into the superradiant phase can be described for a limited time b…
Understanding and Improving Critical Metrology. Quenching Superradiant Light-Matter Systems Beyond the Critical Point
Karol Gietka, Lewis Ruks, Thomas Busch
We carefully examine critical metrology and present an improved critical quantum metrology protocol which relies on quenching a system exhibiting a superradiant quantum phase trans…
Adiabatic critical quantum metrology cannot reach the Heisenberg limit even when shortcuts to adiabaticity are applied
Karol Gietka, Friederike Metz, Tim Keller +1
We show that the quantum Fisher information attained in an adiabatic approach to critical quantum metrology cannot lead to the Heisenberg limit of precision and therefore regular q…
Cavity-enhanced magnetometer with a spinor Bose-Einstein condensate
Karol Gietka, Farokh Mivehvar, Thomas Busch
We propose a novel type of composite light-matter magnetometer based on a transversely driven multi-component Bose-Einstein condensate coupled to two distinct electromagnetic modes…
Simulating the same physics with two distinct Hamiltonians
Karol Gietka, Ayaka Usui, Jianqiao Deng +1
We develop a framework and give an example for situations where two distinct Hamiltonians living in the same Hilbert space can be used to simulate the same physics. As an example o…
Multipartite-Entanglement Dynamics in Regular-to-Ergodic Transition: a Quantum-Fisher-Information approach
Karol Gietka, Jan Chwedeńczuk, Tomasz Wasak +1
The characterization of entanglement is a central problem for the study of quantum many-body dynamics. Here, we propose the quantum Fisher information as a useful tool for the stud…
A supersolid-based gravimeter in a ring cavity
Karol Gietka, Farokh Mivehvar, Helmut Ritsch
We propose a novel type of composite light-matter interferometer based on a supersolid-like phase of a driven Bose-Einstein condensate coupled to a pair of degenerate counterpropag…