While the search interfaces used by common academic digital libraries pro- vide easy access to a wealth of peer-reviewed literature, their interfaces pro- vide little support for exploratory browsing. When faced with a complex search task (such as one that requires knowledge discovery), exploratory browsing is an important first step in an exploratory search process. To more effectively support exploratory browsing, we have designed and implemented a novel academic digital library search interface (KLink Search) with two new features: visually linked keywords and an interactive workspace. To study the potential value of these features, we have conducted a controlled laboratory study with 32 participants, comparing KLink Search to a baseline digital library search interface modelled after that used by IEEE Xplore. Based on subjective opinions, objective performance, and behavioural data, we show the value of adding lightweight visual and interactive features to academic digital library search interfaces to support exploratory browsing.