A microtube implosion driven by ultraintense laser pulses is used to produce
ultrahigh magnetic fields. Due to the laser-produced hot electrons with
energies of mega-electron volts, cold ions in the inner wall surface implode
towards the central axis. By pre-seeding uniform magnetic fields on the
kilotesla order, the Lorenz force induces the Larmor gyromotion of the
imploding ions and electrons. Due to the resultant collective motion of
relativistic charged particles around the central axis, strong spin current
densities of ~ peta-ampere/cm2 are produced with a few tens of nm size,
generating megatesla-order magnetic fields. The underlying physics and
important scaling are revealed by particle simulations and a simple analytical
model. The concept holds promise to open new frontiers in many branches of
fundamental physics and applications in terms of ultrahigh magnetic fields.Comment: 22 pages, 7 figure