Bounds to the speed of evolution a quantum system are fundamental interest in metrology, chemical dynamics, and computation. We derive time-energy uncertainty relation for open systems undergoing general, completely positive, trace preserving which provides bound limit. When is Lindblad form, analogous Mandelstam-Tamm applies unitary case, with role Hamiltonian being played by adjoint generator dynamical semigroup. The utility new exemplified different scenarios, ranging from estimation...

We propose the digital quantum simulation of a minimal $\mathrm{AdS}/\mathrm{CFT}$ model in controllable platforms. consider Sachdev-Ye-Kitaev describing interacting Majorana fermions with randomly distributed all-to-all couplings, encoding nonlocal fermionic operators onto qubits to efficiently implement their dynamics via techniques. Moreover, we also give method for probing nonequilibrium and scrambling information. Finally, our approach serves as protocol reproducing simplified...

Two-photon processes have so far been considered only as resulting from frequency-matched second-order expansions of light-matter interaction, with consequently small coupling strengths. However, a variety novel physical phenomena arises when such values become comparable to the system characteristic frequencies. Here, we propose realistic implementation two-photon quantum Rabi and Dicke models in trapped-ion technologies. In this case, effective two-phonon can be explored all relevant...

We propose a digital quantum simulator of non-Abelian pure-gauge models with superconducting circuit setup. Within the framework link models, we build minimal instance pure SU(2) gauge theory, using triangular plaquettes involving geometric frustration. This realization is least demanding, in terms simulation resources, dynamics. present two architectures that can host simulation, estimating requirements needed to run possible experiments. The proposal establishes path experimental physics...

We determine the complete set of generalized spin squeezing inequalities, given in terms collective angular momentum components, for particles with an arbitrary spin. They can be used experimental detection entanglement ensemble which cannot individually addressed. also present a large criteria involving observables different from coordinates. show that some inequalities to detect k-particle and bound entanglement.

We propose the quantum simulation of a fermion and an antifermion field modes interacting via bosonic mode, present possible implementation with two trapped ions. This platform allows for scalable add-up fermionic modes, represents avenue towards simulations theories in perturbative nonperturbative regimes.

We propose an analog-digital quantum simulation of fermion-fermion scattering mediated by a continuum bosonic modes within circuit electrodynamics scenario. This technology naturally provides strong coupling superconducting qubits with electromagnetic in open transmission line. In this way, we to efficiently simulate fermionic via digital techniques, while consider the complexity line field theories. Therefore, believe that complexity-simulating-complexity concept should become leading...

The controllability of current quantum technologies allows one to implement spin-boson models where two-photon couplings are the dominating terms light-matter interaction. In this case, when coupling strength becomes comparable with characteristic frequencies, a spectral collapse can take place, i.e., discrete system spectrum into continuous band. Here, we analyze thermodynamic limit Dicke model, which describes interaction an ensemble qubits single bosonic mode. We find that there exists...

Abstract Technology based on memristors, resistors with memory whose resistance depends the history of crossing charges, has lately enhanced classical paradigm computation neuromorphic architectures. However, in contrast to known quantized models passive circuit elements, such as inductors, capacitors or resistors, design and realization a quantum memristor is still missing. Here, we introduce concept dissipative device, decoherence mechanism controlled by continuous-measurement feedback...

A complete set of generalized spin-squeezing inequalities is derived for an ensemble particles with arbitrary spin. Our conditions are formulated the first and second moments collective angular momentum coordinates. method mapping spin-1/2 to entanglement spin-j also presented. We apply our obtain a generalization original inequality higher spins. show that, large particle numbers, parameter detection based on one strictly stronger than defined in [A. Sorensen et al., Nature 409, 63 (2001)]....

A system prepared in an unstable quantum state generally decays following exponential law, as environmental decoherence is expected to prevent the decay products from recombining reconstruct initial state. Here we show existence of deviations open systems under very general conditions. Our results are illustrated with exact dynamics Brownian motion and suggest explanation recent experimental observations.

For a quantum-mechanically spread-out particle we investigate method for determining its arrival time at specific location. The procedure is based on the emission of first photon from two-level system moving into laser-illuminated region. resulting temporal distribution explicitly calculated one-dimensional case and compared with axiomatically proposed expressions. As main result show that by means deconvolution one obtains well-known quantum-mechanical probability flux location as limiting...

A quantum simulator is a device engineered to reproduce the properties of an ideal model. It allows study systems that cannot be efficiently simulated on classical computers. While universal computer also simulator, only particular have been up now. Still, there wealth successful cases, such as spin models, chemistry, relativistic physics and phase transitions. Here, we show how design for Majorana equation, non-Hamiltonian wave equation might describe neutrinos other exotic particles beyond...

A universal relation is established between the quantum work probability distribution of an isolated driven system and Loschmidt echo dynamics a two-mode squeezed state. When initial density matrix canonical, purified double thermofield state provides direct measure information scrambling can be related to analytic continuation partition function. Information then described by statistics associated with time-reversal operation on single copy, sudden negation Hamiltonian.

We propose a method for computing n-time correlation functions of arbitrary spinorial, fermionic, and bosonic operators, consisting an efficient quantum algorithm that encodes these correlations in initially added ancillary qubit probe control tasks. For spinorial fermionic systems, the reconstruction requires measurement two ancilla observables, while variables time derivatives same observables are needed. Finally, we provide examples applicable to different platforms frame linear response theory.

We prove, by means of a unified treatment, that the superradiant phase transitions Dicke and classical oscillator limits simple light-matter models are indeed same type. show mean-field approximation is exact in both cases, compute structure location parameter space. extend this study to fuller range models, paying special attention symmetry considerations. uncover general features space parameters these models.

In lumped-element electrical circuit theory, the problem of solving Maxwell's equations in presence media is reduced to two sets equations, constitutive encapsulating local geometry and dynamics a confined energy density, Kirchhoff enforcing conservation charge larger, topological, scale. We develop new geometric systematic description general circuits as first order differential derivable from Lagrangian Rayleigh dissipation function. Through Faddeev-Jackiw method we identify...

Following a consistent geometrical description previously introduced [], we present an exact method for obtaining canonically quantizable Hamiltonian descriptions of nonlinear, nonreciprocal quasilumped electrical networks. We identify and classify singularities arising in the quest general element networks via Faddeev-Jackiw technique. offer systematic solutions to cases considered singular—a major challenge context canonical circuit quantization. The solution relies on correct...

The string propagation equations in axisymmetric spacetimes are exactly solved by quadratures for a planetoid ansatz. This is straight nonoscillating string, radially disposed which rotates uniformly around the symmetry axis of spacetime. In Schwarzschild black holes, stays outside horizon pointing towards origin. de Sitter spacetime its center. We quantize semiclassically these solutions and analyze spin/(${\mathrm{mass}}^{2}$) (Regge) relation planetoids, turns out to be nonlinear.

We present a method for measuring magnetic field gradients with macroscopic singlet states realized ensembles of spin-$j$ particles. While the state is completely insensitive to homogeneous fields, variance its collective spin components highly sensitive gradients. compute dynamics this analytically chain spins and also an ensemble particles given density distribution. find upper bound on how precisely gradient can be estimated from measured data. Based our calculations, differential...

We introduce an exact mapping between the Dirac equation in ($1+1$)-dimensional curved spacetime (DCS) and a multiphoton quantum Rabi model (QRM). A background of black hole requires QRM with one- two-photon terms that can be implemented trapped ion for simulation particles spacetime. illustrate our proposal numerical analysis free fall particle into hole, find Zitterbewegung effect, measurable via oscillatory trajectory particle, persists presence gravity. From duality squeezing term metric...

The physics of high-energy colliders relies on the knowledge different non-perturbative parton correlators, such as distribution functions, that encode information universal hadron structure and are thus main building blocks any factorization theorem underlying process in collision. These functions given terms gauge-invariant light-front operators, they non-local both space real time, intractable by standard lattice techniques due to well-known sign problem. In this paper, we propose a...