Summary: Brüschweiler’s ensemble algorithm requires \(n = \log N\) queries to discover the wanted object from the database of the size \(N\). In this paper, we use a new oracle query function \(g(^{\cdot})\) to improve Brüschweiler’s algorithm such that only one query is needed for searching the single object. Our algorithm extends from one ancillary qubit to \(n\) ancillary qubits. We then construct the oracle query function \(g(^{\cdot})\) satisfying \(g(x) = 0\) for all input x, except for one, say \(x = z\), where \(g(z) = z\). We first prepare \(2n\) qubits, including n qubits for representing the elements and \(n\) ancillary qubits for storing the result of the oracle query function. After one query, we obtain \(z\) by measuring these ancillary qubits. Our algorithm can efficiently discover the wanted object if \(N \leq 2^{30}\) according to current NMR spectrometer technology.