Realizing quantum speed limit in open system with a PT -symmetric trapped-ion qubit

• DOI: 10.1088/1367-2630/ad1a28
• Publication Date: 2024-01-03T22:24:46Z
• Authors: Pengfei Lu; Teng Liu; Yang Liu; Xinxin Rao; Qifeng Lao; Hao Wu; Feng Zhu; Le Luo
• Keywords: Bloch sphere; Time evolution; Hamiltonian (control theory); Classical limit

Abstract Quantum speed limit (QSL), the lower bound of time for transferring an initial state to a target one, is fundamental interest in quantum information processing. Despite that unitary evolution could be well analyzed by either Mandelstam–Tamm or Margolus–Levitin bound, there are still many unknowns QSL open systems. A particularly exciting result about can made arbitrarily small without violating time-energy uncertainty principle, whenever dynamics governed parity-time ( <?CDATA $\mathcal{PT}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi class="MJX-tex-calligraphic">P</mml:mi> class="MJX-tex-calligraphic">T</mml:mi> </mml:mrow> </mml:math> ) symmetric Hamiltonian. Here we study QSLs with both and anti- Hamiltonians, pose as brachistochrone problem on non-Hermitian Bloch sphere. We then use dissipative trapped-ion qubits construct where evolutions reach generalized Margolus-Levitin system. find monotonously decreases increase dissipation strength exhibits chiral dependence These results enable well-controlled knob speeding up manipulation systems, which used control simulation non-unitary dynamics.