PDF (double-sided) - Physics Department, UCSB - University of ...

1.3.1 Scalable Physical System with Well-Defined Qubits
A classical computer can approximate the solution to any problem to arbitrary
precision using only binary operations. Similarly, it has been shown that a
quantum computer can perform any arbitrary computation using only two-state
quantum bits, called “Qubits”, as the operating unit [Barenco et al., 1995]. It
is not necessary to implement “Qudits” with more than two levels as they can
be efficiently simulated by a sufficiently large collection of qubits. The required
number of qubits can grow quickly, though, making it necessary for the proposed
architecture to be scalable.
1.3.2 Initializable to a Simple Fiducial State
The architecture needs to provide a reliable way to initialize its set of qubits
into an arbitrary, but known, starting state. This state can be as trivial as each
qubit being set to “0”.
1.3.3 Sufficiently Long Coherence Times
One of the major problems of many current approaches is the short timescale
over which the information stored inside the qubits dissipates into the environment.
This has prompted the inclusion of a statement about the qubits’
12