Twisted rapid passage is a type of non-adiabatic rapid passage that generates controllablequantum interference effects that were first observed experimentally in 2003. It is shownthat twisted rapid...
Twisted rapid passage is a type of non-adiabatic rapid passage that generates controllable quantum interference effects that were first observed experimentally in 2003. It is shown that twisted rapid passage sweeps can be used to implement a universal set of quantum gates that operate with high-fidelity. The gate set consists of the Hadamard and NOT gates, together with variants of the phase, pi/8, and controlled-phase gates. For each gate g in the universal set, sweep parameter values are provided which numerical simulations indicate will produce a unitary operation that approximates g with error probability less than 10**(-4). Note that all gates in the universal set are implemented using a single family of control-field, and the error probability for each gate falls below the rough-and-ready estimate for the accuracy threshold of 10**(-4).
Twisted rapid passage is a type of non-adiabatic rapid passage that generates controllable quantum interference effects that were first observed experimentally in 2003. It is shown that twisted rapid passage sweeps can be used to implement a universal set of quantum gates $\calGU$ that operate with high-fidelity. The gate set $\calGU$ consists of the Hadamard and NOT gates, together with variants of the phase, π/8, and controlled-phase gates. For each gate g in $\calGU$, sweep parameter values are provided which simulations indicate will produce a unitary operation that approximates g with error probabilityPe<10−4. Note that \textit{all\/} gates in $\calGU$ are implemented using a \textit{single family\/} of control-field, and the error probability for each gate falls below the rough-and-ready estimate for the accuracy threshold Pa∼10−4.
Twisted rapid passage is a type of non-adiabatic rapid passage that gives rise to controllable quantum interference effects that were first observed experimentally in 2003. We show that twisted rapid passage sweeps can be used to implement a universal set of quantum gates that operate with high-fidelity. For each gate in the universal set, sweep parameter values are provided which simulations indicate will yield a quantum gate with error probability P_{e} < 10**(-4). Note that all gates in this universal set are driven by a **single** type of control field (twisted rapid passage), and the error probability for each gate falls below the rough-and-ready estimate for the accuracy threshold P_{a} ~ 10**(-4). The simulations suggest that the universal gate set produced by twisted rapid passage shows promise for use in a fault-tolerant scheme for quantum computing.
Numerical simulation results are presented which suggest that a class of non-adiabatic rapid passage sweeps first realized experimentally in 1991, and which give rise to controllable quantum interference effects observed using NMR in 2003, should be capable of implementing a universal set of quantum gates Gu that operate with high-fidelity. Gu consists of the Hadamard and NOT gates, together with variants of the phase, π/8, and controlled-phase gates. Sweep parameter values are provided which simulations indicate will produce the different gates in Gu, and for each gate, yield an operation with error probability Pe < 10-4. The simulations suggest that the universal gate set produced by these rapid passage sweeps show promise as possible elements of a fault-tolerant scheme for quantum computing.
We provide a further exploration of a type of nonadiabatic rapid passage known as twisted rapid passage (TRP). This class of rapid passage pulses allows a qubit to be driven through resonance multiple times during a single TRP sweep. The multiple resonances give rise to controllable quantum interference effects that provide direct control over qubit transitions so that transitions can be greatly enhanced or suppressed. These quantum interference effects have recently been observed experimentally. We examine here a number of new TRP pulse profiles and show that they can be used to implement a quantum NOT gate that operates both nonadiabatically and with sufficient reliability to surpass the accuracy threshold needed for the gate to be used as part of a fault-tolerant scheme of quantum computation. These new TRP pulse profiles are shown to provide performance advantages over TRP pulses previously considered in the literature.