Analog Sauter-Schwinger effect in semiconductors for spacetime-dependent fields

Abstract

The Sauter-Schwinger effect predicts the creation of electron-positron pairs out of the quantum vacuum via tunneling induced by a strong electric field. Unfortunately, as the required field strength is extremely large, this fundamental prediction of quantum field theory has not been verified experimentally yet. Here, we study under which conditions and approximations the interband tunneling in suitable semiconductors could be effectively governed by the same (Dirac) Hamiltonian, especially for electric fields which depend on space and time. This quantitative analogy would allow us to test some of the predictions (such as the dynamically assisted Sauter-Schwinger effect) in this area by means of these laboratory analogs. PACS numbers: 12.20.-m, 77.22.Jp, 11.15.-q arXiv:1503.07108v4 [cond-mat.mes-hall]

Perturbative methods for assisted nonperturbative pair production

“…To obtain the spectrum we now only have the Fourier integral left, and to perform it we need to specify the shape of the weak field. We begin with the Sauter pulse (14). We perform the Fourier integral with the saddle-point method.…”

“…Many aspects in Schwinger pair production have close analogies in tunneling in semiconductors [14]. In particular, dynamically assisted Schwinger pair production is analogous to the Franz-Keldysh effect [14][15][16][17], where semiconductor tunneling in an electric field is assisted by higher-frequency photons. The Franz-Keldysh effect in QED was very recently studied in [18].…”

“…The Franz-Keldysh effect in QED was very recently studied in [18]. There exists certain replacement rules [14] for translating results for semiconductor tunneling to Schwinger pair production or vice versa. To translate our result (3) for Schwinger pair production to the corresponding result for semiconductor tunneling we have to replace [14] qE crit → c 3 * m 2 * and Σ → ω/(2m * c 2 * ), where c * and m * are semiconductor parameters related to the effective speed of light and the band gap.…”

Sauter–Schwinger effect with a quantum gas

“…The Dirac picture of particle-antiparticle vacuum and the concept of optical lattice band theory is the foundation of our approach. In this framework, we readily measured pair creation and demonstrated that this high-field phenomenon is well-characterized by Landau-Zener tunneling [20,21] as was discussed in [12,[17][18][19].…”

“…Electric fields on this scale are not experimentally accessible; even the largest laboratory fields produced by ultrashort laser pulses [6] fall short, making direct observation of pair creation out of reach of current experiments. Subsequently, analog experiments have been proposed that simulate high-field effects with laboratory accessible energy scales in cold atoms [7][8][9][10], graphene [11][12][13][14][15][16], and other condensed matter systems [12,[17][18][19].…”