Three-level systems now achieve arbitrary single-qubit holonomic gates in a ‘no-jump’ regime, a key advance in quantum control. Wei Li and colleagues from Yanan University have developed a nonadiabatic holonomic scheme using a non-Hermitian Hamiltonian, overcoming limitations of previous methods that either ignored energy loss or were restricted to more complex four-level systems. The approach directly incorporates decay and dephasing, processes that disrupt quantum information, into the design of the control pulses, maintaining gate accuracy despite these effects. The team utilised a three-level system, employing carefully shaped control pulses to perform calculations despite the natural degradation of the system. By directly integrating decay and dephasing, processes that disrupt quantum states, into the control design, this method potentially offers a more stable pathway for quantum computation than existing techniques. Wei Li and colleagues at Yanan University have achieved a key step forward in quantum control by demonstrating arbitrary single-qubit gates within a three-level system, even when energy is lost from the system. This method directly addresses decoherence, the tendency of quantum information to degrade, by incorporating the effects of decay and dephasing, disruptions to quantum states, directly into the design of the control pulses. This is akin to designing a route for manipulating qubits using geometric principles, but without the need for extremely slow, gradual changes; instead, the system is treated as a battery gradually discharging rather than remaining fully charged. The team employed a nonadiabatic holonomic scheme and a biorthogonal framework to achieve this, paving the way for more stable quantum computation. Fast qubit control via dissipation and geometric principles A nonadiabatic holonomic scheme enables faster computation than traditional methods by manipulating qubits using geometric principles, eliminating the need for extremely slow, gradual changes. At its core lies a non-Hermitian Hamiltonian, a mathematical description of a quantum system that accounts
Yanan University Team Develops Nonadiabatic Holonomic Scheme For Robust Single-Qubit Gates
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