Creation of electron-positron plasma with superstrong laser field

Abstract

Abstract. We present a short review of recent progress in studying QED effects of interaction of ultrarelativistic laser pulses with vacuum and e − e + plasma. The development of laser technologies promises very rapid growth of laser intensities in close future already. Two exawatt class facilities (ELI and XCELS, Russia) in Europe are already in the planning stage. Realization of these projects will make available a laser of intensity ∼ 10 26 W/cm 2 or even higher. Therefore, discussion of nonlinear optical effects in vacuum are becoming urgent for experimentalists and are currently gaining much attention. We show that, in spite of the fact that the respective field strength is still essentially less than ES = m 2 c 3 /e = 1.32 · 10 16 V/cm, the nonlinear vacuum effects will be accessible for observation at ELI and XCELS facilities. The most promissory for observation is the effect of pair creation by laser pulse in vacuum. It is shown, that at intensities ∼ 5·10 25 W/cm 2 , creation even of a single pair is accompanied by development of an avalanchelike QED cascade. There exists an important distinctive feature of the laser-induced cascades, as compared with the air showers arising due to primary cosmic ray entering the atmosphere. In our case the laser field plays not only the role of a target (similar to a nucleus in the case of air showers). It is responsible also for acceleration of slow particles. It is shown that the effect of pair creation imposes a natural limit for attainable laser intensity. Apparently, the field strength E ∼ ES is not accessible for pair creating electromagnetic field at all.PACS. 42.50.Ct Quantum description of interaction of light and matter; related experiments -12.20.Ds Specific calculations -52.27.Ep Electron-positron plasmas

Real-time dynamics of lattice gauge theories with a few-qubit quantum computer

“…1). Our few-qubit demonstration is a first step towards simulating real time dynamics in gauge theories, which is fundamental for the understanding of many physical phenomena including the thermalisation after heavy-ion collisions and pair creation studied at high-intensity laser facilities [6,18]. While existing classical numerical methods such as Quantum Monte Carlo have been remarkably successful for describing equilibrium phenomena, no systematic techniques exist to tackle the dynamical longtime behaviour of all but very small systems.…”

Thermalization of electron–positron plasma with quantum degeneracy

“…One of the peculiar properties of such a plasma is that the mean energy per particle exceeds the rest mass of the electron, so it contains pairs of particles (electrons) and antiparticles (positrons). Attempts to create such a plasma in laboratory [2] are linked with the development of ultra-intense lasers [3,4,5,6,7] within large projects, such as ELI 1 and XCELS 2 . A number of interesting phenomena such as relativistic transparency [8], ultrafast thermalization in magnetized plasma [9] and current-driven instability [10] are predicted and observed in such a plasma.…”

U(1) Wilson lattice gauge theories in digital quantum simulators

“…The proposed quantum simulation scheme allows for the experimental study of a wide range of fundamental properties in U(1)-Wilson gauge theories that are of current interest. For example, strong efforts are under way at high-intensity laser facilities such as ELI and XCELS to observe a cascade of particle-antiparticle pairs generated out of the vacuum subject to extreme electric fields [11,12], and several theoretical proposals for the quantum simulation of particle production have been put forward in recent years [14,15,[59][60][61]. The preparation of the true vacuum (the eigenstate of the Schwinger HamiltonianĤ S for finite values of J w m , , ) is challenging for current experiments, as discussed in section 5 below.…”

“…Such a postselection scheme can for example be realized as follows. For each step in the protocol that involves a 12 In the absence of spin flips or undesired state transfers, the quantum states after a full time step are therefore invariant under this type of noise. However, as explained in section 2.2, the active qubits undergo a rotation U y (see figure 3(c)) that changes the reference frame, such that the noise after this rotation is effectively given by dw s = å † U H U y y n n x deph , an interaction that induces spin flips.…”

“…at zero chemical potential) quantum Monte Carlo simulations of lattice gauge theories can be carried out very efficiently [9,10]. However, non-equilibrium properties, as relevant for a variety of high-energy physics phenomena including particle-antiparticle production at high-intensity laser facilities [11,12], are not accessible, due to the fundamental sign (or complex action) problem affecting numerical simulations in real time [13]. In the last few years, several proposals for quantum simulations of real-time dynamics of lattice gauge theories have been put forward [14][15][16], based on a variety of platforms ranging from cold atoms in optical lattices [17][18][19][20][21][22][23], to superconducting circuits [24,25] and trapped ions [26,27].…”