  Quantum superposition and entanglement of physical states can be harnessed to
solve some problems which are intractable on a classical computer implementing
binary logic. Several algorithms have been proposed to utilize the quantum
nature of physical states and solve important problems. For example, Shor's
quantum algorithm is extremely important in the field of cryptography since it
factors large numbers exponentially faster than any known classical algorithm.
Another celebrated example is the Grovers quantum algorithm. These algorithms
can only be implemented on a quantum computer which operates on quantum bits
(qubits). Rudimentary implementations of quantum processor have already been
achieved through linear optical components, ion traps, NMR etc. However
demonstration of a solid state quantum processor had been elusive till DiCarlo
et al demonstrated two qubit algorithms in superconducting quantum processor.
Though this has been a significant step, scalable semiconductor based room
temperature quantum computing is yet to be found. Such a technology could
benefit from the vast experience of the semiconductor industry. Hence, here we
present a reconfigurable semiconductor quantum logic device (SQuaLD) which
operates on the position and spin degree of freedom of the electrons in the
device. Based on a few recent experiments, we believe SQuaLD is experimentally
feasible. Moreover, using a well known quantum simulation method, we show that
quantum algorithms (such as Deutsch Jozsa, Grover search) as well as universal
classical logic operations (such as NAND gate) can be implemented in SQuaLD.
Thus, we argue that SQuaLD is a strong candidate for the future quantum logic
processor since it also satisfies the DiVincenzo criteria for quantum logic
application as well as the five essential characteristics for classical logic
applications.
