Entanglement of superconducting qubits via acceleration radiation

Abstract

We show that simulated relativistic motion can generate entanglement between artificial atoms and protect them from spontaneous emission. We consider a pair of superconducting qubits coupled to a resonator mode, where the modulation of the coupling strength can mimic the harmonic motion of the qubits at relativistic speeds, generating acceleration radiation. We find the optimal feasible conditions for generating a stationary entangled state between the qubits when they are initially prepared in their ground state. Furthermore, we analyse the effects of motion on the probability of spontaneous emission in the standard scenarios of single-atom and two-atom superradiance, where one or two excitations are initially present. Finally, we show that relativistic motion induces sub-radiance and can generate a Zeno-like effect, preserving the excitations from radiative decay.

One-dimensional sections of exotic spacetimes with superconducting circuits

“…Actually, this could be the most interesting point of the experiment since it can only be addressed in a fully quantum simulator. By coupling superconducting qubits to the SQUID array and simulating their motion [15][16][17], we could analyse the projection of closed timelike curves in the radial direction of Kerr and Gödel spacetimes. A detailed analysis lies beyond the scope of the current work.…”

“…Several modern quantum systems are typically used in these simulations. One of them is superconducting circuits, where relativistic effects in quantum mechanics and quantum field theory have been analysed, both in a direct or a simulated fashion [11][12][13][14][15][16][17]. Indeed, in [9] we proposed a superconducting circuit setup for the simulation of a traversable wormhole spacetime.…”

Entanglement through qubit motion and the dynamical Casimir effect

“…The second line of the equation contains the interaction of the qubits with their cavities, being k i the wave vector of the cavity, g i the maximum intensity of its coupling, σ x i the first Pauli operator of the qubit and x qi (t) simulated trajectory of qubit motion. Experimentally, the product k i x qi (t) is actually f = φ(t)/φ 0 with φ 0 the quantum of magnetic flux and φ(t) the flux through the SQUID [19,20] that may be controlled from the outside with a typical nanosecond resolution. The third line contains the interaction between the cavities, being g 1,2 (t) the time-dependent coupling assuming that the boundary conditions produced by the SQUID do not destroy the structure of normal field modes or make resonances of new modes with the qubits.…”

Relativity and quantum optics: accelerated atoms in optical cavities

“…Detector initially in excited state (3,15), (4,14), (5,13), (6, 11), (7,8), (7,9), (8, 2), (8, 3), (8, 4)}. For the initially excited detector, the number expectation values are underestimated only for those modes with associated energies that are close to the detector's gap for low accelerations; for higher accelerations this will get shifted in l direction mainly due to the Doppler shift.…”